diff --git a/.github/workflows/bootstrap-pull-request.yaml b/.github/workflows/bootstrap-pull-request.yaml
index 5b3a165e0..40d133a26 100644
--- a/.github/workflows/bootstrap-pull-request.yaml
+++ b/.github/workflows/bootstrap-pull-request.yaml
@@ -49,6 +49,20 @@ jobs:
           git config --global user.email 'github-actions@github.com'
           git config --global user.name 'github-actions'
 
+      - uses: ./bootstrap-pull-request
+        id: when-namespace-branch-not-exists
+        continue-on-error: true
+        with:
+          overlay: overlay-${{ github.run_id }}
+          namespace: pr-${{ github.event.number }}
+          destination-repository: ${{ github.repository }}
+          error-if-namespace-branch-not-exists: true
+          prebuilt-branch: bootstrap-pull-request-e2e-prebuilt-${{ github.run_id }}
+          namespace-manifest: bootstrap-pull-request/tests/fixtures/namespace.yaml
+          substitute-variables: NAMESPACE=pr-${{ github.event.number }}
+      - if: steps.when-namespace-branch-not-exists.outcome != 'failure'
+        run: exit 1
+
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           ref: ${{ github.head_ref }} # avoid "shallow update not allowed" error
diff --git a/bootstrap-pull-request/README.md b/bootstrap-pull-request/README.md
index b44bb04e9..ff85cab56 100644
--- a/bootstrap-pull-request/README.md
+++ b/bootstrap-pull-request/README.md
@@ -148,6 +148,19 @@ All placeholders will be replaced during copying the namespace manifest.
 For example, if `NAMESPACE=pr-123` is given by `substitute-variables` input,
 this action will replace `${NAMESPACE}` with `pr-123`.
 
+## Consistency considerations
+
+### Namespace branch lost
+
+1. When a pull request is created, git-push-service action writes the service manifests to the namespace branch.
+1. The namespace branch is deleted accidentally.
+1. When the label is added to the pull request, this action creates the namespace branch with all services from the prebuilt branch.
+   It confuses the user because the namespace branch does not contain the change of the pull request.
+
+```yaml
+error-if-namespace-branch-not-exists: ${{ github.event.action == 'labeled' }}
+```
+
 ## Specification
 
 See [action.yaml](action.yaml).
diff --git a/bootstrap-pull-request/action.yaml b/bootstrap-pull-request/action.yaml
index 8933d0f93..0fdbe1f1a 100644
--- a/bootstrap-pull-request/action.yaml
+++ b/bootstrap-pull-request/action.yaml
@@ -15,6 +15,10 @@ inputs:
   destination-repository:
     description: Destination repository
     required: true
+  error-if-namespace-branch-not-exists:
+    description: Throw an error if the namespace branch does not exist
+    required: false
+    default: "false"
   prebuilt-branch:
     description: Name of prebuilt branch in the destination repository. This input will be required in the future release.
     required: false
diff --git a/bootstrap-pull-request/src/main.ts b/bootstrap-pull-request/src/main.ts
index ea39e6da2..408f52ce6 100644
--- a/bootstrap-pull-request/src/main.ts
+++ b/bootstrap-pull-request/src/main.ts
@@ -7,6 +7,7 @@ const main = async (): Promise<void> => {
     namespace: core.getInput('namespace', { required: true }),
     sourceRepository: core.getInput('source-repository', { required: true }),
     destinationRepository: core.getInput('destination-repository', { required: true }),
+    errorIfNamespaceBranchNotExists: core.getBooleanInput('error-if-namespace-branch-not-exists', { required: true }),
     prebuiltBranch: core.getInput('prebuilt-branch', { required: false }) || undefined,
     destinationRepositoryToken: core.getInput('destination-repository-token', { required: true }),
     namespaceManifest: core.getInput('namespace-manifest') || undefined,
diff --git a/bootstrap-pull-request/src/run.ts b/bootstrap-pull-request/src/run.ts
index 20caf2e02..465a7aa9e 100644
--- a/bootstrap-pull-request/src/run.ts
+++ b/bootstrap-pull-request/src/run.ts
@@ -10,6 +10,7 @@ type Inputs = {
   namespace: string
   sourceRepository: string
   destinationRepository: string
+  errorIfNamespaceBranchNotExists: boolean
   prebuiltBranch: string | undefined
   destinationRepositoryToken: string
   namespaceManifest: string | undefined
@@ -97,8 +98,19 @@ const checkoutPrebuiltBranch = async (inputs: Inputs, prebuiltBranch: string) =>
 
 const checkoutNamespaceBranch = async (inputs: Inputs) => {
   const namespaceBranch = getNamespaceBranch(inputs)
+  if (inputs.errorIfNamespaceBranchNotExists) {
+    return await core.group(
+      `Checking out the namespace branch: ${namespaceBranch}`,
+      async () =>
+        await git.checkout({
+          repository: inputs.destinationRepository,
+          branch: namespaceBranch,
+          token: inputs.destinationRepositoryToken,
+        }),
+    )
+  }
   return await core.group(
-    `Checking out the namespace branch: ${namespaceBranch}`,
+    `Checking out or init the namespace branch: ${namespaceBranch}`,
     async () =>
       await git.checkoutOrInitRepository({
         repository: inputs.destinationRepository,