diff --git a/.github/workflows/base-deploy.yml b/.github/workflows/base-deploy.yml
index 59bf5e8f..2e01aaec 100644
--- a/.github/workflows/base-deploy.yml
+++ b/.github/workflows/base-deploy.yml
@@ -153,21 +153,246 @@ jobs:
             ./dist/lambda.zip \
             --region eu-west-2
 
-      - name: "Upload lambda artifact for the current workflow"
+      - name: "Upload lambda artifact for downstream jobs"
         uses: actions/upload-artifact@v6
         with:
           name: lambda-${{ needs.metadata.outputs.tag }}
           path: ./dist/lambda.zip
 
-  deploy:
-    name: "Deploy to ${{ needs.metadata.outputs.environment }}"
+  sign-lambda-artifact:
+    name: "Sign lambda artifact for PreProd"
+    if: ${{ needs.metadata.outputs.environment == 'preprod' }}
+    runs-on: ubuntu-latest
+    needs: [ metadata, download-lambda-artifact ]
+    timeout-minutes: 45
+    permissions:
+      id-token: write
+      contents: read
+    environment: preprod
+    steps:
+      - name: "Checkout repository at ref"
+        uses: actions/checkout@v6
+        with:
+          ref: ${{ needs.metadata.outputs.ref }}
+          fetch-depth: 0
+
+      - name: "Setup Terraform"
+        uses: hashicorp/setup-terraform@v3
+        with:
+          terraform_version: ${{ needs.metadata.outputs.terraform_version }}
+
+      - name: "Configure AWS Credentials"
+        uses: aws-actions/configure-aws-credentials@v6
+        with:
+          role-to-assume: arn:aws:iam::${{ secrets.AWS_ACCOUNT_ID }}:role/service-roles/github-actions-api-deployment-role
+          aws-region: eu-west-2
+
+      - name: "Download unsigned lambda artifact from current workflow"
+        uses: actions/download-artifact@v7
+        with:
+          name: lambda-${{ needs.metadata.outputs.tag }}
+          path: ./dist
+
+      - name: "Terraform Init (PREPROD api-layer)"
+        env:
+          ENVIRONMENT: preprod
+          WORKSPACE: "default"
+        run: |
+          echo "Running: make terraform env=$ENVIRONMENT workspace=$WORKSPACE stack=api-layer tf-command=init"
+          make terraform env=$ENVIRONMENT stack=api-layer tf-command=init workspace=$WORKSPACE
+        working-directory: ./infrastructure
+
+      - name: "Extract PREPROD Terraform outputs"
+        id: preprod_tf_output
+        run: |
+          BUCKET=$(terraform output -raw lambda_artifact_bucket)
+          PROFILE=$(terraform output -raw signing_profile_name)
+          echo "bucket_name=$BUCKET" >> $GITHUB_OUTPUT
+          echo "signing_profile_name=$PROFILE" >> $GITHUB_OUTPUT
+        working-directory: ./infrastructure/stacks/api-layer
+
+      - name: "Upload unsigned lambda artifact to PREPROD S3"
+        run: |
+          aws s3 cp ./dist/lambda.zip \
+            s3://${{ steps.preprod_tf_output.outputs.bucket_name }}/artifacts/${{ needs.metadata.outputs.tag }}/lambda.zip \
+            --region eu-west-2
+
+      - name: "Get uploaded source object version"
+        id: source_object
+        run: |
+          VERSION_ID=$(aws s3api head-object \
+            --bucket "${{ steps.preprod_tf_output.outputs.bucket_name }}" \
+            --key "artifacts/${{ needs.metadata.outputs.tag }}/lambda.zip" \
+            --query 'VersionId' \
+            --output text \
+            --region eu-west-2)
+          echo "version_id=$VERSION_ID" >> $GITHUB_OUTPUT
+
+      - name: "Start signing job"
+        id: signing
+        env:
+          SIGNING_PROFILE_NAME: ${{ steps.preprod_tf_output.outputs.signing_profile_name }}
+        run: |
+          JOB_ID=$(aws signer start-signing-job \
+            --source "s3={bucketName=${{ steps.preprod_tf_output.outputs.bucket_name }},key=artifacts/${{ needs.metadata.outputs.tag }}/lambda.zip,version=${{ steps.source_object.outputs.version_id }}}" \
+            --destination "s3={bucketName=${{ steps.preprod_tf_output.outputs.bucket_name }},prefix=signed-artifacts/${{ needs.metadata.outputs.tag }}/}" \
+            --profile-name "$SIGNING_PROFILE_NAME" \
+            --query 'jobId' \
+            --output text \
+            --region eu-west-2)
+          echo "job_id=$JOB_ID" >> $GITHUB_OUTPUT
+
+      - name: "Wait for signing job"
+        run: |
+          aws signer wait successful-signing-job \
+            --job-id "${{ steps.signing.outputs.job_id }}" \
+            --region eu-west-2
+
+      - name: "Resolve signed artifact location"
+        id: signed_object
+        run: |
+          SIGNED_BUCKET=$(aws signer describe-signing-job \
+            --job-id "${{ steps.signing.outputs.job_id }}" \
+            --region eu-west-2 \
+            --query 'signedObject.s3.bucketName' \
+            --output text)
+
+          SIGNED_KEY=$(aws signer describe-signing-job \
+            --job-id "${{ steps.signing.outputs.job_id }}" \
+            --region eu-west-2 \
+            --query 'signedObject.s3.key' \
+            --output text)
+
+          echo "bucket_name=$SIGNED_BUCKET" >> $GITHUB_OUTPUT
+          echo "object_key=$SIGNED_KEY" >> $GITHUB_OUTPUT
+
+      - name: "Download signed lambda artifact"
+        run: |
+          aws s3 cp \
+            "s3://${{ steps.signed_object.outputs.bucket_name }}/${{ steps.signed_object.outputs.object_key }}" \
+            ./dist/lambda.zip \
+            --region eu-west-2
+
+      - name: "Upload signed lambda artifact for current workflow"
+        uses: actions/upload-artifact@v6
+        with:
+          name: lambda-signed-${{ needs.metadata.outputs.tag }}
+          path: ./dist/lambda.zip
+
+
+  deploy-preprod:
+    name: "Deploy to preprod"
+    if: ${{ needs.metadata.outputs.environment == 'preprod' }}
+    runs-on: ubuntu-latest
+    needs: [metadata, download-lambda-artifact, sign-lambda-artifact]
+    timeout-minutes: 45
+    permissions:
+      id-token: write
+      contents: write
+    environment: preprod
+    steps:
+      - name: "Checkout repository at ref"
+        uses: actions/checkout@v6
+        with:
+          ref: ${{ needs.metadata.outputs.ref }}
+          fetch-depth: 0
+
+      - name: "Setup Terraform"
+        uses: hashicorp/setup-terraform@v3
+        with:
+          terraform_version: ${{ needs.metadata.outputs.terraform_version }}
+
+      - name: "Download signed Lambda Artifact"
+        uses: actions/download-artifact@v7
+        with:
+          name: lambda-signed-${{ needs.metadata.outputs.tag }}
+          path: ./dist
+
+      - name: "Configure AWS Credentials (IAM Bootstrap Role)"
+        uses: aws-actions/configure-aws-credentials@v6
+        with:
+          role-to-assume: arn:aws:iam::${{ secrets.AWS_ACCOUNT_ID }}:role/service-roles/github-actions-iam-bootstrap-role
+          aws-region: eu-west-2
+
+      - name: "Deploy IAM roles (iams-developer-roles stack)"
+        working-directory: ./infrastructure
+        run: |
+          make terraform env=preprod stack=iams-developer-roles tf-command=apply workspace=default
+
+      - name: "Configure AWS Credentials (Main Deployment Role)"
+        uses: aws-actions/configure-aws-credentials@v6
+        with:
+          role-to-assume: arn:aws:iam::${{ secrets.AWS_ACCOUNT_ID }}:role/service-roles/github-actions-api-deployment-role
+          aws-region: eu-west-2
+
+      - name: "Terraform Apply"
+        env:
+          ENVIRONMENT: preprod
+          WORKSPACE: "default"
+          TF_VAR_API_CA_CERT: ${{ secrets.API_CA_CERT }}
+          TF_VAR_API_CLIENT_CERT: ${{ secrets.API_CLIENT_CERT }}
+          TF_VAR_API_PRIVATE_KEY_CERT: ${{ secrets.API_PRIVATE_KEY_CERT }}
+          TF_VAR_SPLUNK_HEC_TOKEN: ${{ secrets.SPLUNK_HEC_TOKEN }}
+          TF_VAR_SPLUNK_HEC_ENDPOINT: ${{ secrets.SPLUNK_HEC_ENDPOINT }}
+          TF_VAR_OPERATOR_EMAILS: ${{ vars.SECRET_ROTATION_OPERATOR_EMAILS }}
+          TF_VAR_PROXYGEN_PRIVATE_KEY_PTL: ${{ secrets.PROXYGEN_PRIVATE_KEY_PTL }}
+          TF_VAR_PROXYGEN_PRIVATE_KEY_PROD: ${{ secrets.PROXYGEN_PRIVATE_KEY_PROD }}
+        working-directory: ./infrastructure
+        shell: bash
+        run: |
+          set -euo pipefail
+          mkdir -p ./build
+          echo "Running: make terraform env=$ENVIRONMENT workspace=$WORKSPACE stack=networking tf-command=apply"
+          make terraform env=$ENVIRONMENT stack=networking tf-command=apply workspace=$WORKSPACE
+          echo "Running: make terraform env=$ENVIRONMENT workspace=$WORKSPACE stack=api-layer tf-command=apply"
+          make terraform env=$ENVIRONMENT stack=api-layer tf-command=apply workspace=$WORKSPACE
+
+      - name: "Extract S3 bucket name from Terraform output"
+        id: tf_output
+        run: |
+          BUCKET=$(terraform output -raw lambda_artifact_bucket)
+          echo "bucket_name=$BUCKET" >> $GITHUB_OUTPUT
+        working-directory: ./infrastructure/stacks/api-layer
+
+      - name: "Validate Feature Toggles"
+        env:
+          ENV: preprod
+        run: |
+          pip install boto3
+          python scripts/feature_toggle/validate_toggles.py
+
+      - name: "Tag and Release"
+        env:
+          ENVIRONMENT: preprod
+          REF: ${{ needs.metadata.outputs.ref }}
+          INPUT_RELEASE_TYPE: ${{ inputs.release_type }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_REPOSITORY: ${{ github.repository }}
+        run: |
+          pip install requests
+          python scripts/workflow/tag_and_release.py
+
+      - name: "Capture release tag"
+        id: release_tag
+        run: |
+          echo "release_tag=$(cat release_tag.txt)" >> $GITHUB_OUTPUT
+
+      - name: "Upload lambda artifact to S3"
+        run: |
+          aws s3 cp ./dist/lambda.zip \
+            s3://${{ steps.tf_output.outputs.bucket_name }}/artifacts/${{ steps.release_tag.outputs.release_tag }}/lambda.zip \
+            --region eu-west-2
+
+  deploy-prod:
+    name: "Deploy to prod"
+    if: ${{ needs.metadata.outputs.environment == 'prod' }}
     runs-on: ubuntu-latest
     needs: [metadata, download-lambda-artifact]
     timeout-minutes: 45
     permissions:
       id-token: write
       contents: write
-    environment: ${{ needs.metadata.outputs.environment }}
+    environment: prod
     steps:
       - name: "Checkout repository at ref"
         uses: actions/checkout@v6
@@ -195,7 +420,7 @@ jobs:
       - name: "Deploy IAM roles (iams-developer-roles stack)"
         working-directory: ./infrastructure
         run: |
-          make terraform env=${{ needs.metadata.outputs.environment }} stack=iams-developer-roles tf-command=apply workspace=default
+          make terraform env=prod stack=iams-developer-roles tf-command=apply workspace=default
 
       - name: "Configure AWS Credentials (Main Deployment Role)"
         uses: aws-actions/configure-aws-credentials@v6
@@ -205,7 +430,7 @@ jobs:
 
       - name: "Terraform Apply"
         env:
-          ENVIRONMENT: ${{ needs.metadata.outputs.environment }}
+          ENVIRONMENT: prod
           WORKSPACE: "default"
           TF_VAR_API_CA_CERT: ${{ secrets.API_CA_CERT }}
           TF_VAR_API_CLIENT_CERT: ${{ secrets.API_CLIENT_CERT }}
@@ -215,7 +440,6 @@ jobs:
           TF_VAR_OPERATOR_EMAILS: ${{ vars.SECRET_ROTATION_OPERATOR_EMAILS }}
           TF_VAR_PROXYGEN_PRIVATE_KEY_PTL: ${{ secrets.PROXYGEN_PRIVATE_KEY_PTL }}
           TF_VAR_PROXYGEN_PRIVATE_KEY_PROD: ${{ secrets.PROXYGEN_PRIVATE_KEY_PROD }}
-
         working-directory: ./infrastructure
         shell: bash
         run: |
@@ -235,15 +459,14 @@ jobs:
 
       - name: "Validate Feature Toggles"
         env:
-          ENV: ${{ needs.metadata.outputs.environment }}
+          ENV: prod
         run: |
           pip install boto3
           python scripts/feature_toggle/validate_toggles.py
 
       - name: "Tag and Release"
-        if: ${{ needs.metadata.outputs.environment == 'preprod' || needs.metadata.outputs.environment == 'prod' }}
         env:
-          ENVIRONMENT: ${{ needs.metadata.outputs.environment }}
+          ENVIRONMENT: prod
           REF: ${{ needs.metadata.outputs.ref }}
           INPUT_RELEASE_TYPE: ${{ inputs.release_type }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -266,7 +489,7 @@ jobs:
   regression-tests:
     name: "Regression Tests"
     if: ${{ needs.metadata.outputs.environment == 'preprod' }}
-    needs: deploy
+    needs: deploy-preprod
     permissions:
       id-token: write
       contents: read
diff --git a/infrastructure/modules/lambda/lambda.tf b/infrastructure/modules/lambda/lambda.tf
index db67f93a..e44e948d 100644
--- a/infrastructure/modules/lambda/lambda.tf
+++ b/infrastructure/modules/lambda/lambda.tf
@@ -1,7 +1,7 @@
 resource "aws_lambda_function" "eligibility_signposting_lambda" {
   #checkov:skip=CKV_AWS_116: No deadletter queue is configured for this Lambda function, as the requests are synchronous
   #checkov:skip=CKV_AWS_115: Concurrent execution limit will be set at APIM level, not at Lambda level
-  #checkov:skip=CKV_AWS_272: Skipping code signing but flagged to create ticket to investigate on ELI-238
+  #checkov:skip=CKV_AWS_272: Code signing not yet enforced in prod - tracked for removal when prod enforcement is enabled
   # If the file is not in the current working directory you will need to include a
   # path.module in the filename.
   filename      = var.file_name
@@ -11,6 +11,8 @@ resource "aws_lambda_function" "eligibility_signposting_lambda" {
 
   source_code_hash = filebase64sha256(var.file_name)
 
+  code_signing_config_arn = contains(var.environments_with_signing, var.environment) ? aws_lambda_code_signing_config.signing_config.arn : null
+
   runtime     = var.runtime
   timeout     = 30
   memory_size = 2048
@@ -39,10 +41,10 @@ resource "aws_lambda_function" "eligibility_signposting_lambda" {
   }
 
   layers = compact([
-      var.environment == "prod" || var.environment == "preprod" ?
-      "arn:aws:lambda:${var.region}:580247275435:layer:LambdaInsightsExtension:${var.lambda_insights_extension_version}"
-      :
-      null
+    var.environment == "prod" || var.environment == "preprod" ?
+    "arn:aws:lambda:${var.region}:580247275435:layer:LambdaInsightsExtension:${var.lambda_insights_extension_version}"
+    :
+    null
   ])
 
 
@@ -66,4 +68,3 @@ resource "aws_lambda_provisioned_concurrency_config" "campaign_pc" {
   qualifier                         = aws_lambda_alias.campaign_alias[0].name
   provisioned_concurrent_executions = var.provisioned_concurrency_count
 }
-
diff --git a/infrastructure/modules/lambda/variables.tf b/infrastructure/modules/lambda/variables.tf
index ffc76497..e6366e56 100644
--- a/infrastructure/modules/lambda/variables.tf
+++ b/infrastructure/modules/lambda/variables.tf
@@ -88,3 +88,9 @@ variable "hashing_secret_name" {
   description = "hashing secret name"
   type        = string
 }
+
+variable "environments_with_signing" {
+  description = "List of environments where Lambda code signing is enabled; enforcement behaviour depends on the configured code signing policy"
+  type        = list(string)
+  default     = ["test"]
+}
diff --git a/infrastructure/stacks/api-layer/lambda.tf b/infrastructure/stacks/api-layer/lambda.tf
index b3eba156..cb38efb7 100644
--- a/infrastructure/stacks/api-layer/lambda.tf
+++ b/infrastructure/stacks/api-layer/lambda.tf
@@ -18,7 +18,7 @@ module "eligibility_signposting_lambda_function" {
   environment                               = var.environment
   runtime                                   = "python3.13"
   lambda_func_name                          = "${terraform.workspace == "default" ? "" : "${terraform.workspace}-"}eligibility_signposting_api"
-  security_group_ids = [data.aws_security_group.main_sg.id]
+  security_group_ids                        = [data.aws_security_group.main_sg.id]
   vpc_intra_subnets                         = [for v in data.aws_subnet.private_subnets : v.id]
   file_name                                 = "../../../dist/lambda.zip"
   handler                                   = "eligibility_signposting_api.app.lambda_handler"
@@ -33,6 +33,7 @@ module "eligibility_signposting_lambda_function" {
   stack_name                                = local.stack_name
   provisioned_concurrency_count             = 5
   api_domain_name                           = local.api_domain_name
+  environments_with_signing                 = ["test", "preprod"]
 }
 
 
@@ -69,7 +70,7 @@ resource "aws_lambda_function" "create_secret_lambda" {
     variables = { SECRET_NAME = module.secrets_manager.aws_hashing_secret_name }
   }
   vpc_config {
-    subnet_ids = [for s in data.aws_subnet.private_subnets : s.id]
+    subnet_ids         = [for s in data.aws_subnet.private_subnets : s.id]
     security_group_ids = [data.aws_security_group.main_sg.id]
   }
 }
@@ -98,7 +99,7 @@ resource "aws_lambda_function" "promote_secret_lambda" {
     variables = { SECRET_NAME = module.secrets_manager.aws_hashing_secret_name }
   }
   vpc_config {
-    subnet_ids = [for s in data.aws_subnet.private_subnets : s.id]
+    subnet_ids         = [for s in data.aws_subnet.private_subnets : s.id]
     security_group_ids = [data.aws_security_group.main_sg.id]
   }
 }