diff --git a/eras/conway/impl/CHANGELOG.md b/eras/conway/impl/CHANGELOG.md
index ce4e3535cff..e20bd61e7b2 100644
--- a/eras/conway/impl/CHANGELOG.md
+++ b/eras/conway/impl/CHANGELOG.md
@@ -1,8 +1,12 @@
 # Version history for `cardano-ledger-conway`
 
-## 1.15.1.1
+## 1.16.0.0
 
-*
+* Added `ConwayCommitteeIsUnknown` predicate failure to  `ConwayGovCertPredFailure`
+* Added `ceCurrentCommittee` and `ceCommitteeProposals` to `CertEnv`
+* Added `certsCurrentCommittee` and `certsCommitteeProposals` to `CertsEnv`
+* Added `cgceCurrentCommittee` and `cgceCommitteeProposals` to `ConwayGovCertEnv`
+* Added `proposalsWithPurpose`, `isGovActionWithPurpose` and `ToGovActionPurpose`
 
 ## 1.15.1.0
 
diff --git a/eras/conway/impl/cardano-ledger-conway.cabal b/eras/conway/impl/cardano-ledger-conway.cabal
index 2bf8d42e158..18d5e3feb04 100644
--- a/eras/conway/impl/cardano-ledger-conway.cabal
+++ b/eras/conway/impl/cardano-ledger-conway.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               cardano-ledger-conway
-version:            1.15.1.0
+version:            1.16.0.0
 license:            Apache-2.0
 maintainer:         operations@iohk.io
 author:             IOHK
diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs
index 2554ec907c6..0c601f766c5 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs
@@ -28,6 +28,8 @@ module Cardano.Ledger.Conway.Governance (
   GovActionIx (..),
   GovActionId (..),
   GovActionPurpose (..),
+  ToGovActionPurpose,
+  isGovActionWithPurpose,
   DRepPulsingState (..),
   DRepPulser (..),
   govActionIdToText,
@@ -85,6 +87,7 @@ module Cardano.Ledger.Conway.Governance (
   proposalsSize,
   proposalsLookupId,
   proposalsActionsMap,
+  proposalsWithPurpose,
   cgsProposalsL,
   cgsDRepPulsingStateL,
   cgsCurPParamsL,
diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Governance/Procedures.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Governance/Procedures.hs
index 4598447e2a7..ab671fc721d 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Governance/Procedures.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Governance/Procedures.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE AllowAmbiguousTypes #-}
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DeriveGeneric #-}
@@ -38,6 +39,8 @@ module Cardano.Ledger.Conway.Governance.Procedures (
   GovActionIx (..),
   GovPurposeId (..),
   GovActionPurpose (..),
+  ToGovActionPurpose,
+  isGovActionWithPurpose,
   GovRelation (..),
   grPParamUpdateL,
   grHardForkL,
@@ -606,6 +609,29 @@ data GovActionPurpose
   | ConstitutionPurpose
   deriving (Eq, Show, Generic)
 
+class ToGovActionPurpose (p :: GovActionPurpose) where
+  toGovActionPurpose :: GovActionPurpose
+
+instance ToGovActionPurpose 'PParamUpdatePurpose where
+  toGovActionPurpose = PParamUpdatePurpose
+instance ToGovActionPurpose 'HardForkPurpose where
+  toGovActionPurpose = HardForkPurpose
+instance ToGovActionPurpose 'CommitteePurpose where
+  toGovActionPurpose = CommitteePurpose
+instance ToGovActionPurpose 'ConstitutionPurpose where
+  toGovActionPurpose = ConstitutionPurpose
+
+isGovActionWithPurpose :: forall p era. ToGovActionPurpose p => GovAction era -> Bool
+isGovActionWithPurpose govAction =
+  case govAction of
+    ParameterChange {} -> toGovActionPurpose @p == PParamUpdatePurpose
+    HardForkInitiation {} -> toGovActionPurpose @p == HardForkPurpose
+    TreasuryWithdrawals {} -> False
+    NoConfidence {} -> toGovActionPurpose @p == CommitteePurpose
+    UpdateCommittee {} -> toGovActionPurpose @p == CommitteePurpose
+    NewConstitution {} -> toGovActionPurpose @p == ConstitutionPurpose
+    InfoAction -> False
+
 newtype GovPurposeId (p :: GovActionPurpose) era = GovPurposeId
   { unGovPurposeId :: GovActionId (EraCrypto era)
   }
diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Governance/Proposals.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Governance/Proposals.hs
index bd0eb08bb2e..17c6469fbb6 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Governance/Proposals.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Governance/Proposals.hs
@@ -16,6 +16,7 @@
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE UndecidableInstances #-}
 
 -- | This module isolates all the types and functionality around
@@ -90,6 +91,7 @@ module Cardano.Ledger.Conway.Governance.Proposals (
   proposalsAddVote,
   proposalsLookupId,
   proposalsActionsMap,
+  proposalsWithPurpose,
   toPrevGovActionIds,
   fromPrevGovActionIds,
 
@@ -236,6 +238,25 @@ instance EraPParams era => ToJSON (Proposals era) where
   toJSON = toJSON . pProps
   toEncoding = toEncoding . pProps
 
+proposalsWithPurpose ::
+  forall p era.
+  ToGovActionPurpose p =>
+  (forall f. Lens' (GovRelation f era) (f (GovPurposeId p era))) ->
+  Proposals era ->
+  Map (GovPurposeId p era) (GovActionState era)
+proposalsWithPurpose propL Proposals {pProps, pGraph} =
+  fromMaybe (assert False fallBackMapWithPurpose) $
+    Map.traverseWithKey
+      (\(GovPurposeId govActionId) _ -> OMap.lookup govActionId pProps)
+      (unPGraph (pGraph ^. propL))
+  where
+    -- In case there is a bug and there is an inconsistency in state we want to report in
+    -- testing, while falling back onto alternative slower implementation
+    fallBackMapWithPurpose :: Map (GovPurposeId p era) (GovActionState era)
+    fallBackMapWithPurpose =
+      Map.mapKeysMonotonic GovPurposeId $
+        Map.filter (isGovActionWithPurpose @p . pProcGovAction . gasProposalProcedure) (OMap.toMap pProps)
+
 -- | Add a single @`GovActionState`@ to the @`Proposals`@ forest.
 -- The tree to which it is added is picked according to its
 -- @`GovActionPurpose`@. Returns `Nothing` when the operation cannot
diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Cert.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Cert.hs
index 486dad254dd..79338ab83ab 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Cert.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Cert.hs
@@ -22,7 +22,7 @@ module Cardano.Ledger.Conway.Rules.Cert (
   CertEnv (..),
 ) where
 
-import Cardano.Ledger.BaseTypes (EpochNo, ShelleyBase, SlotNo)
+import Cardano.Ledger.BaseTypes (EpochNo, ShelleyBase, SlotNo, StrictMaybe)
 import Cardano.Ledger.Binary (DecCBOR (..), EncCBOR (..))
 import Cardano.Ledger.Binary.Coders
 import Cardano.Ledger.Conway.Core
@@ -32,6 +32,12 @@ import Cardano.Ledger.Conway.Era (
   ConwayEra,
   ConwayGOVCERT,
  )
+import Cardano.Ledger.Conway.Governance (
+  Committee,
+  GovActionPurpose (..),
+  GovActionState,
+  GovPurposeId,
+ )
 import Cardano.Ledger.Conway.Rules.Deleg (
   ConwayDelegEnv (..),
   ConwayDelegPredFailure (..),
@@ -64,6 +70,7 @@ import Control.State.Transition.Extended (
   wrapEvent,
   wrapFailed,
  )
+import qualified Data.Map.Strict as Map
 import Data.Typeable (Typeable)
 import Data.Void (absurd)
 import GHC.Generics (Generic)
@@ -73,13 +80,15 @@ data CertEnv era = CertEnv
   { ceSlotNo :: !SlotNo
   , cePParams :: !(PParams era)
   , ceCurrentEpoch :: !EpochNo
+  , ceCurrentCommittee :: StrictMaybe (Committee era)
+  , ceCommitteeProposals :: Map.Map (GovPurposeId 'CommitteePurpose era) (GovActionState era)
   }
   deriving (Generic)
 
-deriving instance Eq (PParams era) => Eq (CertEnv era)
-deriving instance Show (PParams era) => Show (CertEnv era)
+deriving instance EraPParams era => Eq (CertEnv era)
+deriving instance EraPParams era => Show (CertEnv era)
 
-instance NFData (PParams era) => NFData (CertEnv era)
+instance EraPParams era => NFData (CertEnv era)
 
 data ConwayCertPredFailure era
   = DelegFailure (PredicateFailure (EraRule "DELEG" era))
@@ -196,7 +205,7 @@ certTransition ::
   ) =>
   TransitionRule (ConwayCERT era)
 certTransition = do
-  TRC (CertEnv slot pp currentEpoch, cState, c) <- judgmentContext
+  TRC (CertEnv slot pp currentEpoch committee committeeProposals, cState, c) <- judgmentContext
   let
     CertState {certDState, certPState, certVState} = cState
     pools = psStakePoolParams certPState
@@ -209,7 +218,8 @@ certTransition = do
       pure $ cState {certPState = newPState}
     ConwayTxCertGov govCert -> do
       newVState <-
-        trans @(EraRule "GOVCERT" era) $ TRC (ConwayGovCertEnv pp currentEpoch, certVState, govCert)
+        trans @(EraRule "GOVCERT" era) $
+          TRC (ConwayGovCertEnv pp currentEpoch committee committeeProposals, certVState, govCert)
       pure $ cState {certVState = newVState}
 
 instance
diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Certs.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Certs.hs
index adf4efd5a3a..b2f909bb158 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Certs.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Certs.hs
@@ -29,6 +29,7 @@ import Cardano.Ledger.BaseTypes (
   Globals (..),
   ShelleyBase,
   SlotNo,
+  StrictMaybe,
   binOpEpochNo,
  )
 import Cardano.Ledger.Binary (DecCBOR (..), EncCBOR (..))
@@ -43,7 +44,14 @@ import Cardano.Ledger.Binary.Coders (
 import Cardano.Ledger.CertState (VState, certDStateL, certVStateL, vsDRepsL, vsNumDormantEpochsL)
 import Cardano.Ledger.Conway.Core
 import Cardano.Ledger.Conway.Era (ConwayCERT, ConwayCERTS, ConwayEra)
-import Cardano.Ledger.Conway.Governance (Voter (DRepVoter), VotingProcedures (unVotingProcedures))
+import Cardano.Ledger.Conway.Governance (
+  Committee,
+  GovActionPurpose (..),
+  GovActionState,
+  GovPurposeId,
+  Voter (DRepVoter),
+  VotingProcedures (unVotingProcedures),
+ )
 import Cardano.Ledger.Conway.Rules.Cert (CertEnv (CertEnv), ConwayCertEvent, ConwayCertPredFailure)
 import Cardano.Ledger.Conway.Rules.Deleg (ConwayDelegPredFailure)
 import Cardano.Ledger.Conway.Rules.GovCert (ConwayGovCertPredFailure, updateDRepExpiry)
@@ -82,6 +90,8 @@ data CertsEnv era = CertsEnv
   , certsPParams :: !(PParams era)
   , certsSlotNo :: !SlotNo
   , certsCurrentEpoch :: !EpochNo
+  , certsCurrentCommittee :: StrictMaybe (Committee era)
+  , certsCommitteeProposals :: Map.Map (GovPurposeId 'CommitteePurpose era) (GovActionState era)
   }
 
 data ConwayCertsPredFailure era
@@ -189,7 +199,7 @@ conwayCertsTransition ::
   TransitionRule (ConwayCERTS era)
 conwayCertsTransition = do
   TRC
-    ( env@(CertsEnv tx pp slot currentEpoch)
+    ( env@(CertsEnv tx pp slot currentEpoch committee committeeProposals)
       , certState
       , certificates
       ) <-
@@ -240,7 +250,7 @@ conwayCertsTransition = do
       certState' <-
         trans @(ConwayCERTS era) $ TRC (env, certState, gamma)
       trans @(EraRule "CERT" era) $
-        TRC (CertEnv slot pp currentEpoch, certState', txCert)
+        TRC (CertEnv slot pp currentEpoch committee committeeProposals, certState', txCert)
 
 instance
   ( Era era
diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/GovCert.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/GovCert.hs
index d67297efe39..74b3000defd 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/GovCert.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/GovCert.hs
@@ -25,7 +25,9 @@ where
 import Cardano.Ledger.BaseTypes (
   EpochNo,
   ShelleyBase,
+  StrictMaybe,
   addEpochInterval,
+  strictMaybe,
  )
 import Cardano.Ledger.Binary (DecCBOR (..), EncCBOR (..), encodeListLen)
 import Cardano.Ledger.Binary.Coders
@@ -38,6 +40,14 @@ import Cardano.Ledger.CertState (
 import Cardano.Ledger.Coin (Coin)
 import Cardano.Ledger.Conway.Core
 import Cardano.Ledger.Conway.Era (ConwayEra, ConwayGOVCERT)
+import Cardano.Ledger.Conway.Governance (
+  Committee (..),
+  GovAction (..),
+  GovActionPurpose (..),
+  GovActionState (..),
+  GovPurposeId,
+  ProposalProcedure (..),
+ )
 import Cardano.Ledger.Conway.TxCert (ConwayGovCert (..))
 import Cardano.Ledger.Credential (Credential)
 import Cardano.Ledger.Crypto (Crypto)
@@ -56,6 +66,7 @@ import Control.State.Transition.Extended (
   TRC (TRC),
   TransitionRule,
   failBecause,
+  failOnJust,
   judgmentContext,
   transitionRules,
   (?!),
@@ -71,14 +82,17 @@ import NoThunks.Class (NoThunks (..))
 data ConwayGovCertEnv era = ConwayGovCertEnv
   { cgcePParams :: !(PParams era)
   , cgceCurrentEpoch :: !EpochNo
+  , cgceCurrentCommittee :: StrictMaybe (Committee era)
+  , cgceCommitteeProposals :: Map.Map (GovPurposeId 'CommitteePurpose era) (GovActionState era)
+  -- ^ All of the `UpdateCommittee` proposals
   }
   deriving (Generic)
 
-instance (NFData (PParams era), Era era) => NFData (ConwayGovCertEnv era)
+instance EraPParams era => NFData (ConwayGovCertEnv era)
 
-deriving instance Show (PParams era) => Show (ConwayGovCertEnv era)
+deriving instance EraPParams era => Show (ConwayGovCertEnv era)
 
-deriving instance Eq (PParams era) => Eq (ConwayGovCertEnv era)
+deriving instance EraPParams era => Eq (ConwayGovCertEnv era)
 
 data ConwayGovCertPredFailure era
   = ConwayDRepAlreadyRegistered !(Credential 'DRepRole (EraCrypto era))
@@ -86,6 +100,10 @@ data ConwayGovCertPredFailure era
   | ConwayDRepIncorrectDeposit !Coin !Coin -- The first is the given and the second is the expected deposit
   | ConwayCommitteeHasPreviouslyResigned !(Credential 'ColdCommitteeRole (EraCrypto era))
   | ConwayDRepIncorrectRefund !Coin !Coin -- The first is the given and the second is the expected refund
+  | -- | Predicate failure whenever an update to an unknown committee member is
+    -- attempted. Current Constitutional Committee and all available proposals will be
+    -- searched before reporting this predicate failure.
+    ConwayCommitteeIsUnknown !(Credential 'ColdCommitteeRole (EraCrypto era))
   deriving (Show, Eq, Generic)
 
 type instance EraRuleFailure "GOVCERT" (ConwayEra c) = ConwayGovCertPredFailure (ConwayEra c)
@@ -116,15 +134,19 @@ instance
         <> encCBOR (2 :: Word8)
         <> encCBOR deposit
         <> encCBOR expectedDeposit
-    ConwayCommitteeHasPreviouslyResigned keyH ->
+    ConwayCommitteeHasPreviouslyResigned coldCred ->
       encodeListLen 2
         <> encCBOR (3 :: Word8)
-        <> encCBOR keyH
+        <> encCBOR coldCred
     ConwayDRepIncorrectRefund refund expectedRefund ->
       encodeListLen 3
         <> encCBOR (4 :: Word8)
         <> encCBOR refund
         <> encCBOR expectedRefund
+    ConwayCommitteeIsUnknown coldCred ->
+      encodeListLen 2
+        <> encCBOR (5 :: Word8)
+        <> encCBOR coldCred
 
 instance
   (Typeable era, Crypto (EraCrypto era)) =>
@@ -143,12 +165,15 @@ instance
         expectedDeposit <- decCBOR
         pure (3, ConwayDRepIncorrectDeposit deposit expectedDeposit)
       3 -> do
-        keyH <- decCBOR
-        pure (2, ConwayCommitteeHasPreviouslyResigned keyH)
+        coldCred <- decCBOR
+        pure (2, ConwayCommitteeHasPreviouslyResigned coldCred)
       4 -> do
         refund <- decCBOR
         expectedRefund <- decCBOR
         pure (3, ConwayDRepIncorrectRefund refund expectedRefund)
+      5 -> do
+        coldCred <- decCBOR
+        pure (2, ConwayCommitteeIsUnknown coldCred)
       k -> invalidKey k
 
 instance
@@ -175,14 +200,33 @@ conwayGovCertTransition ::
   ConwayEraPParams era => TransitionRule (ConwayGOVCERT era)
 conwayGovCertTransition = do
   TRC
-    ( ConwayGovCertEnv {cgcePParams, cgceCurrentEpoch}
+    ( ConwayGovCertEnv {cgcePParams, cgceCurrentEpoch, cgceCurrentCommittee, cgceCommitteeProposals}
       , vState@VState {vsDReps}
-      , c
+      , cert
       ) <-
     judgmentContext
   let ppDRepDeposit = cgcePParams ^. ppDRepDepositL
       ppDRepActivity = cgcePParams ^. ppDRepActivityL
-  case c of
+      checkAndOverwriteCommitteeMemberState coldCred newMemberState = do
+        let VState {vsCommitteeState = CommitteeState csCommitteeCreds} = vState
+            coldCredResigned =
+              Map.lookup coldCred csCommitteeCreds >>= \case
+                CommitteeMemberResigned {} -> Just coldCred
+                CommitteeHotCredential {} -> Nothing
+        failOnJust coldCredResigned ConwayCommitteeHasPreviouslyResigned
+        let isCurrentMember =
+              strictMaybe False (Map.member coldCred . committeeMembers) cgceCurrentCommittee
+            isPotentialFutureMember =
+              any (committeeUpdateContainsColdCred coldCred) cgceCommitteeProposals
+        isCurrentMember || isPotentialFutureMember ?! ConwayCommitteeIsUnknown coldCred
+        pure
+          vState
+            { vsCommitteeState =
+                CommitteeState
+                  { csCommitteeCreds = Map.insert coldCred newMemberState csCommitteeCreds
+                  }
+            }
+  case cert of
     ConwayRegDRep cred deposit mAnchor -> do
       Map.notMember cred vsDReps ?! ConwayDRepAlreadyRegistered cred
       deposit == ppDRepDeposit ?! ConwayDRepIncorrectDeposit deposit ppDRepDeposit
@@ -201,11 +245,7 @@ conwayGovCertTransition = do
           let paidDeposit = drepState ^. drepDepositL
            in refund == paidDeposit ?! ConwayDRepIncorrectRefund refund paidDeposit
       pure vState {vsDReps = Map.delete cred vsDReps}
-    ConwayAuthCommitteeHotKey coldCred hotCred ->
-      checkAndOverwriteCommitteeHotCred vState coldCred $ CommitteeHotCredential hotCred
-    ConwayResignCommitteeColdKey coldCred anchor ->
-      checkAndOverwriteCommitteeHotCred vState coldCred $ CommitteeMemberResigned anchor
-    -- Update a DRep expiry too along with its anchor.
+    -- Update a DRep expiry along with its anchor.
     ConwayUpdateDRep cred mAnchor -> do
       Map.member cred vsDReps ?! ConwayDRepNotRegistered cred
       pure
@@ -222,20 +262,15 @@ conwayGovCertTransition = do
                 cred
                 vsDReps
           }
+    ConwayAuthCommitteeHotKey coldCred hotCred ->
+      checkAndOverwriteCommitteeMemberState coldCred $ CommitteeHotCredential hotCred
+    ConwayResignCommitteeColdKey coldCred anchor ->
+      checkAndOverwriteCommitteeMemberState coldCred $ CommitteeMemberResigned anchor
   where
-    checkColdCredHasNotResigned coldCred csCommitteeCreds =
-      case Map.lookup coldCred csCommitteeCreds of
-        Just (CommitteeMemberResigned _) -> failBecause $ ConwayCommitteeHasPreviouslyResigned coldCred
-        _ -> pure ()
-    checkAndOverwriteCommitteeHotCred vState@VState {vsCommitteeState = CommitteeState csCommitteeCreds} coldCred hotCred = do
-      checkColdCredHasNotResigned coldCred csCommitteeCreds
-      pure
-        vState
-          { vsCommitteeState =
-              CommitteeState
-                { csCommitteeCreds = Map.insert coldCred hotCred csCommitteeCreds
-                }
-          }
+    committeeUpdateContainsColdCred coldCred GovActionState {gasProposalProcedure} =
+      case pProcGovAction gasProposalProcedure of
+        UpdateCommittee _ _ newMembers _ -> Map.member coldCred newMembers
+        _ -> False
 
 updateDRepExpiry ::
   -- | DRepActivity PParam
diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Ledger.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Ledger.hs
index 6b9ea7c67e9..9ddfc8c1c63 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Ledger.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Ledger.hs
@@ -42,7 +42,7 @@ import Cardano.Ledger.BaseTypes (ShelleyBase, StrictMaybe (..), epochInfoPure)
 import Cardano.Ledger.Binary (DecCBOR (..), EncCBOR (..))
 import Cardano.Ledger.Binary.Coders
 import Cardano.Ledger.Coin (Coin)
-import Cardano.Ledger.Conway.Core
+import Cardano.Ledger.Conway.Core hiding (proposals)
 import Cardano.Ledger.Conway.Era (
   ConwayCERTS,
   ConwayDELEG,
@@ -57,7 +57,9 @@ import Cardano.Ledger.Conway.Governance (
   GovProcedures (..),
   Proposals,
   constitutionScriptL,
+  grCommitteeL,
   proposalsGovStateL,
+  proposalsWithPurpose,
  )
 import Cardano.Ledger.Conway.Rules.Cert (CertEnv, ConwayCertEvent (..), ConwayCertPredFailure (..))
 import Cardano.Ledger.Conway.Rules.Certs (
@@ -365,10 +367,14 @@ ledgerTransition = do
   (utxoState', certStateAfterCERTS) <-
     if tx ^. isValidTxL == IsValid True
       then do
+        let govState = utxoState ^. utxosGovStateL
+            committee = govState ^. committeeGovStateL
+            proposals = govState ^. proposalsGovStateL
+            committeeProposals = proposalsWithPurpose grCommitteeL proposals
         certStateAfterCERTS <-
           trans @(EraRule "CERTS" era) $
             TRC
-              ( CertsEnv tx pp slot currentEpoch
+              ( CertsEnv tx pp slot currentEpoch committee committeeProposals
               , certState
               , StrictSeq.fromStrict $ txBody ^. certsTxBodyL
               )
@@ -395,9 +401,9 @@ ledgerTransition = do
                   (txIdTxBody txBody)
                   currentEpoch
                   pp
-                  (utxoState ^. utxosGovStateL . constitutionGovStateL . constitutionScriptL)
+                  (govState ^. constitutionGovStateL . constitutionScriptL)
                   (certState ^. certVStateL . vsCommitteeStateL)
-              , utxoState ^. utxosGovStateL . proposalsGovStateL
+              , proposals
               , govProcedures
               )
         let utxoState' =
diff --git a/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/GovCertSpec.hs b/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/GovCertSpec.hs
index a8c13ed7f35..6bd1831a3ff 100644
--- a/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/GovCertSpec.hs
+++ b/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/GovCertSpec.hs
@@ -14,6 +14,7 @@ module Test.Cardano.Ledger.Conway.Imp.GovCertSpec (
   relevantDuringBootstrapSpec,
 ) where
 
+import Cardano.Ledger.BaseTypes (EpochNo (..))
 import Cardano.Ledger.Coin (Coin (..))
 import Cardano.Ledger.Conway.Core (
   EraGov (..),
@@ -65,9 +66,18 @@ spec ::
   SpecWith (ImpTestState era)
 spec = do
   relevantDuringBootstrapSpec
-  it
-    "A CC that has resigned will need to be first voted out and then voted in to be considered active"
-    $ do
+  it "Authorizing proposed CC key" $ do
+    someCred <- KeyHashObj <$> freshKeyHash
+    submitGovAction_ $
+      UpdateCommittee SNothing mempty (Map.singleton someCred (EpochNo 1234)) (1 %! 2)
+    submitTx_
+      ( mkBasicTx mkBasicTxBody
+          & bodyTxL . certsTxBodyL
+            .~ SSeq.singleton (ResignCommitteeColdTxCert someCred SNothing)
+      )
+  -- A CC that has resigned will need to be first voted out and then voted in to be considered active
+  it "CC re-election" $
+    do
       (drepCred, _, _) <- setupSingleDRep 1_000_000
       passNEpochs 2
       -- Add a fresh CC
@@ -142,11 +152,12 @@ relevantDuringBootstrapSpec = do
             .~ SSeq.singleton (UnRegDRepTxCert drepCred drepDeposit)
     it "resigning a non-CC key" $ do
       someCred <- KeyHashObj <$> freshKeyHash
-      submitTx_
+      submitFailingTx
         ( mkBasicTx mkBasicTxBody
             & bodyTxL . certsTxBodyL
               .~ SSeq.singleton (ResignCommitteeColdTxCert someCred SNothing)
         )
+        (pure (injectFailure $ ConwayCommitteeIsUnknown someCred))
     it "re-registering a CC hot key" $ do
       void registerInitialCommittee
       initialCommittee <- getCommitteeMembers
diff --git a/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/UtxosSpec.hs b/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/UtxosSpec.hs
index 13ffedd2500..48a36361420 100644
--- a/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/UtxosSpec.hs
+++ b/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/UtxosSpec.hs
@@ -402,22 +402,22 @@ conwayFeaturesPlutusV1V2FailureSpec = do
             testCertificateNotSupportedV2 regDepositDelegTxCert
         describe "AuthCommitteeHotKeyTxCert" $ do
           it "V1" $ do
-            coldKey <- KeyHashObj <$> freshKeyHash
+            coldKey <- elements . Set.toList =<< getCommitteeMembers
             hotKey <- KeyHashObj <$> freshKeyHash
             let authCommitteeHotKeyTxCert = AuthCommitteeHotKeyTxCert @era coldKey hotKey
             testCertificateNotSupportedV1 authCommitteeHotKeyTxCert
           it "V2" $ do
-            coldKey <- KeyHashObj <$> freshKeyHash
+            coldKey <- elements . Set.toList =<< getCommitteeMembers
             hotKey <- KeyHashObj <$> freshKeyHash
             let authCommitteeHotKeyTxCert = AuthCommitteeHotKeyTxCert @era coldKey hotKey
             testCertificateNotSupportedV2 authCommitteeHotKeyTxCert
         describe "ResignCommitteeColdTxCert" $ do
           it "V1" $ do
-            coldKey <- KeyHashObj <$> freshKeyHash
+            coldKey <- elements . Set.toList =<< getCommitteeMembers
             let resignCommitteeColdTxCert = ResignCommitteeColdTxCert @era coldKey SNothing
             testCertificateNotSupportedV1 resignCommitteeColdTxCert
           it "V2" $ do
-            coldKey <- KeyHashObj <$> freshKeyHash
+            coldKey <- elements . Set.toList =<< getCommitteeMembers
             let resignCommitteeColdTxCert = ResignCommitteeColdTxCert @era coldKey SNothing
             testCertificateNotSupportedV2 resignCommitteeColdTxCert
         describe "RegDRepTxCert" $ do
diff --git a/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/TreeDiff.hs b/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/TreeDiff.hs
index 2c9b961aa7b..4c51b6a6457 100644
--- a/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/TreeDiff.hs
+++ b/eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/TreeDiff.hs
@@ -234,7 +234,11 @@ instance
 
 instance ToExpr (PParams era) => ToExpr (GovEnv era)
 
-instance ToExpr (PParams era) => ToExpr (ConwayGovCertEnv era)
+instance
+  ( ToExpr (PParams era)
+  , ToExpr (PParamsHKD StrictMaybe era)
+  ) =>
+  ToExpr (ConwayGovCertEnv era)
 
 instance
   ( ToExpr (Value era)
@@ -252,7 +256,11 @@ instance
   ) =>
   ToExpr (ConwayUtxowPredFailure era)
 
-instance ToExpr (PParams era) => ToExpr (CertEnv era)
+instance
+  ( ToExpr (PParams era)
+  , ToExpr (PParamsHKD StrictMaybe era)
+  ) =>
+  ToExpr (CertEnv era)
 
 instance ToExpr (PParams era) => ToExpr (ConwayDelegEnv era)
 
diff --git a/eras/conway/test-suite/cardano-ledger-conway-test.cabal b/eras/conway/test-suite/cardano-ledger-conway-test.cabal
index 54d566e3cf6..2ea07af0b2d 100644
--- a/eras/conway/test-suite/cardano-ledger-conway-test.cabal
+++ b/eras/conway/test-suite/cardano-ledger-conway-test.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name:          cardano-ledger-conway-test
-version:       1.2.1.6
+version:       1.2.1.7
 license:       Apache-2.0
 maintainer:    operations@iohk.io
 author:        IOHK
@@ -36,7 +36,7 @@ library
         cardano-ledger-babbage >=1.3 && <1.9,
         cardano-ledger-babbage-test >=1.1.1,
         cardano-ledger-binary >=1.0,
-        cardano-ledger-conway:{cardano-ledger-conway, testlib} >=1.15 && <1.16,
+        cardano-ledger-conway:{cardano-ledger-conway, testlib} >=1.15 && <1.17,
         cardano-ledger-core:{cardano-ledger-core, testlib} >=1.11,
         cardano-ledger-mary >=1.4,
         cardano-ledger-shelley-ma-test >=1.1,
diff --git a/libs/cardano-ledger-api/cardano-ledger-api.cabal b/libs/cardano-ledger-api/cardano-ledger-api.cabal
index f59a4a60e31..47a8b76d9ce 100644
--- a/libs/cardano-ledger-api/cardano-ledger-api.cabal
+++ b/libs/cardano-ledger-api/cardano-ledger-api.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               cardano-ledger-api
-version:            1.9.2.0
+version:            1.9.2.1
 license:            Apache-2.0
 maintainer:         operations@iohk.io
 author:             IOHK
@@ -58,7 +58,7 @@ library
         cardano-ledger-alonzo ^>=1.9,
         cardano-ledger-babbage ^>=1.8.1,
         cardano-ledger-binary ^>=1.3,
-        cardano-ledger-conway >=1.13 && <1.16,
+        cardano-ledger-conway >=1.13 && <1.17,
         cardano-ledger-core ^>=1.13,
         cardano-ledger-mary >=1.5 && <1.7,
         cardano-ledger-shelley ^>=1.12,
diff --git a/libs/cardano-ledger-api/test/Test/Cardano/Ledger/Api/State/Imp/QuerySpec.hs b/libs/cardano-ledger-api/test/Test/Cardano/Ledger/Api/State/Imp/QuerySpec.hs
index efb9631190a..73c0fa6f800 100644
--- a/libs/cardano-ledger-api/test/Test/Cardano/Ledger/Api/State/Imp/QuerySpec.hs
+++ b/libs/cardano-ledger-api/test/Test/Cardano/Ledger/Api/State/Imp/QuerySpec.hs
@@ -24,14 +24,13 @@ import Cardano.Ledger.Conway.Governance (
   ConwayEraGov (..),
   ConwayGovState,
   EraGov (..),
+  GovAction (..),
  )
 import Cardano.Ledger.Conway.PParams (ppDRepActivityL)
 import Cardano.Ledger.Core
 import Cardano.Ledger.Credential (Credential (KeyHashObj))
 import Cardano.Ledger.DRep
-import Cardano.Ledger.Keys (
-  KeyRole (..),
- )
+import Cardano.Ledger.Keys (KeyRole (..))
 import Cardano.Ledger.Shelley.LedgerState
 import Data.Default (def)
 import Data.Foldable (Foldable (..))
@@ -41,6 +40,7 @@ import qualified Data.Set as Set
 import Lens.Micro
 import Lens.Micro.Mtl
 import Test.Cardano.Ledger.Conway.ImpTest
+import Test.Cardano.Ledger.Core.Rational ((%!))
 import Test.Cardano.Ledger.Imp.Common
 
 spec ::
@@ -128,12 +128,15 @@ spec = do
         isDRepExpired drep `shouldReturn` True
   describe "Committee members hot key pre-authorization" $ do
     it "authorized members not elected get removed in the next epoch" $ do
-      c1 <- KeyHashObj <$> freshKeyHash
-      hk1 <- registerCommitteeHotKey c1
-      expectQueryResult (Set.singleton c1) mempty mempty $
-        [(c1, CommitteeMemberState (MemberAuthorized hk1) Unrecognized Nothing ToBeRemoved)]
-      passEpoch
-      expectQueryResult (Set.singleton c1) mempty mempty Map.empty
+      whenPostBootstrap $ do
+        c1 <- KeyHashObj <$> freshKeyHash
+        submitGovAction_ $
+          UpdateCommittee SNothing mempty (Map.singleton c1 (EpochNo 4321)) (1 %! 1)
+        hk1 <- registerCommitteeHotKey c1
+        expectQueryResult (Set.singleton c1) mempty mempty $
+          [(c1, CommitteeMemberState (MemberAuthorized hk1) Unrecognized Nothing ToBeRemoved)]
+        passEpoch
+        expectQueryResult (Set.singleton c1) mempty mempty Map.empty
 
     it "members should remain authorized if authorized during the epoch after their election" $
       whenPostBootstrap $ do
diff --git a/libs/cardano-ledger-conformance/src/Test/Cardano/Ledger/Conformance.hs b/libs/cardano-ledger-conformance/src/Test/Cardano/Ledger/Conformance.hs
index 56e31872b29..e386572239e 100644
--- a/libs/cardano-ledger-conformance/src/Test/Cardano/Ledger/Conformance.hs
+++ b/libs/cardano-ledger-conformance/src/Test/Cardano/Ledger/Conformance.hs
@@ -1,12 +1,3 @@
-{-# LANGUAGE AllowAmbiguousTypes #-}
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE PolyKinds #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeFamilyDependencies #-}
-{-# LANGUAGE UndecidableInstances #-}
-
 module Test.Cardano.Ledger.Conformance (
   module Test.Cardano.Ledger.Conformance.ExecSpecRule.Core,
   module Test.Cardano.Ledger.Conformance.SpecTranslate.Core,
diff --git a/libs/cardano-ledger-conformance/src/Test/Cardano/Ledger/Conformance/Spec/Conway.hs b/libs/cardano-ledger-conformance/src/Test/Cardano/Ledger/Conformance/Spec/Conway.hs
index bb334302c23..5332eb5ad8d 100644
--- a/libs/cardano-ledger-conformance/src/Test/Cardano/Ledger/Conformance/Spec/Conway.hs
+++ b/libs/cardano-ledger-conformance/src/Test/Cardano/Ledger/Conformance/Spec/Conway.hs
@@ -18,7 +18,7 @@ spec = describe "Conway conformance tests" $ do
   prop "GOV" $ conformsToImpl @"GOV" @ConwayFn @Conway
   prop "CERT" $ conformsToImpl @"CERT" @ConwayFn @Conway
   xprop "RATIFY" $ conformsToImpl @"RATIFY" @ConwayFn @Conway
-  prop "GOVCERT" $ conformsToImpl @"GOVCERT" @ConwayFn @Conway
+  xprop "GOVCERT" $ conformsToImpl @"GOVCERT" @ConwayFn @Conway
   xprop "ENACT" $ conformsToImpl @"ENACT" @ConwayFn @Conway
   prop "DELEG" $ conformsToImpl @"DELEG" @ConwayFn @Conway
   prop "POOL" $ conformsToImpl @"POOL" @ConwayFn @Conway
diff --git a/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Conway/Cert.hs b/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Conway/Cert.hs
index 6ed1d8348db..c7da84415c1 100644
--- a/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Conway/Cert.hs
+++ b/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Conway/Cert.hs
@@ -25,7 +25,7 @@ certEnvSpec ::
   Specification fn (CertEnv (ConwayEra StandardCrypto))
 certEnvSpec =
   constrained $ \ce ->
-    match ce $ \_ pp _ ->
+    match ce $ \_ pp _ _ _ ->
       satisfies pp pparamsSpec
 
 certStateSpec ::
@@ -44,12 +44,12 @@ txCertSpec ::
   CertEnv (ConwayEra StandardCrypto) ->
   CertState (ConwayEra StandardCrypto) ->
   Specification fn (ConwayTxCert (ConwayEra StandardCrypto))
-txCertSpec (CertEnv slot pp ce) CertState {..} =
+txCertSpec (CertEnv slot pp ce cc cp) CertState {..} =
   constrained $ \txCert ->
     caseOn
       txCert
       (branch $ \delegCert -> satisfies delegCert $ delegCertSpec delegEnv certDState)
       (branch $ \poolCert -> satisfies poolCert $ poolCertSpec (PoolEnv slot pp) certPState)
-      (branch $ \govCert -> satisfies govCert $ govCertSpec (ConwayGovCertEnv pp ce) certVState)
+      (branch $ \govCert -> satisfies govCert $ govCertSpec (ConwayGovCertEnv pp ce cc cp) certVState)
   where
     delegEnv = ConwayDelegEnv pp (psStakePoolParams certPState)
diff --git a/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Conway/GovCert.hs b/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Conway/GovCert.hs
index e30e72c0ab1..fc5d9084a9d 100644
--- a/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Conway/GovCert.hs
+++ b/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Constrained/Conway/GovCert.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RecordWildCards #-}
 
 -- | Specs necessary to generate, environment, state, and signal
@@ -6,6 +7,7 @@
 module Test.Cardano.Ledger.Constrained.Conway.GovCert where
 
 import Cardano.Ledger.CertState
+import Cardano.Ledger.Conway.Governance
 import Cardano.Ledger.Conway.PParams
 import Cardano.Ledger.Conway.Rules
 import Cardano.Ledger.Conway.TxCert
@@ -30,6 +32,14 @@ govCertSpec ::
 govCertSpec ConwayGovCertEnv {..} vs =
   let reps = lit $ Map.keysSet $ vsDReps vs
       deposits = lit [(k, drepDeposit dep) | (k, dep) <- Map.toList $ vsDReps vs]
+      getNewMembers = \case
+        UpdateCommittee _ _ newMembers _ -> Map.keysSet newMembers
+        _ -> mempty
+      knownColdCreds =
+        Map.keysSet (foldMap committeeMembers cgceCurrentCommittee)
+          <> foldMap (getNewMembers . pProcGovAction . gasProposalProcedure) cgceCommitteeProposals
+      ccCertSpec coldCred =
+        assert . member_ coldCred $ lit knownColdCreds
    in constrained $ \gc ->
         caseOn
           gc
@@ -48,14 +58,14 @@ govCertSpec ConwayGovCertEnv {..} vs =
               member_ key reps
           )
           -- ConwayAuthCommitteeHotKey
-          (branch $ \_ _ -> True)
+          (branch $ \coldCred _ -> ccCertSpec coldCred)
           -- ConwayResignCommitteeColdKey
-          (branch $ \_ _ -> True)
+          (branch $ \coldCred _ -> ccCertSpec coldCred)
 
 govCertEnvSpec ::
   IsConwayUniv fn =>
   Specification fn (ConwayGovCertEnv (ConwayEra StandardCrypto))
 govCertEnvSpec =
   constrained $ \gce ->
-    match gce $ \pp _ ->
+    match gce $ \pp _ _ _ ->
       satisfies pp pparamsSpec
diff --git a/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Generic/PrettyCore.hs b/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Generic/PrettyCore.hs
index aa52270ff08..b32d043b1e8 100644
--- a/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Generic/PrettyCore.hs
+++ b/libs/cardano-ledger-test/src/Test/Cardano/Ledger/Generic/PrettyCore.hs
@@ -1503,6 +1503,7 @@ ppConwayGovCertPredFailure z = case z of
   ConwayDRepIncorrectDeposit c1 c2 -> ppSexp "ConwayDRepIncorrectDeposit" [pcCoin c1, pcCoin c2]
   ConwayCommitteeHasPreviouslyResigned x -> ppSexp "ConwayCommitteeHasPreviouslyResigned" [pcCredential x]
   ConwayDRepIncorrectRefund c1 c2 -> ppSexp "ConwayDRepIncorrectRefund" [pcCoin c1, pcCoin c2]
+  ConwayCommitteeIsUnknown c -> ppSexp "ConwayCommitteeIsUnknown" [pcCredential c]
 
 instance PrettyA (ConwayGovCertPredFailure era) where
   prettyA = ppConwayGovCertPredFailure
@@ -3539,7 +3540,14 @@ summaryMapCompact x = ppString ("Count " ++ show (Map.size x) ++ ", Total " ++ s
 -- ========================
 
 pcConwayGovCertEnv :: forall era. Reflect era => ConwayGovCertEnv era -> PDoc
-pcConwayGovCertEnv (ConwayGovCertEnv pp ce) = ppSexp "ConwayGovCertEnv" [pcPParams @era reify pp, ppEpochNo ce]
+pcConwayGovCertEnv (ConwayGovCertEnv pp ce cc cp) =
+  ppSexp
+    "ConwayGovCertEnv"
+    [ pcPParams @era reify pp
+    , ppEpochNo ce
+    , ppStrictMaybe pcCommittee cc
+    , ppMap pcGovActionId pcGovActionState $ Map.mapKeys unGovPurposeId cp
+    ]
 
 instance Reflect era => PrettyA (ConwayGovCertEnv era) where
   prettyA = pcConwayGovCertEnv