diff --git a/app/models/clusters/cluster.rb b/app/models/clusters/cluster.rb
index 8c044c86c47..8bb44b0ce40 100644
--- a/app/models/clusters/cluster.rb
+++ b/app/models/clusters/cluster.rb
@@ -100,12 +100,6 @@ module Clusters
 
     scope :default_environment, -> { where(environment_scope: DEFAULT_ENVIRONMENT) }
 
-    scope :missing_kubernetes_namespace, -> (kubernetes_namespaces) do
-      subquery = kubernetes_namespaces.select('1').where('clusters_kubernetes_namespaces.cluster_id = clusters.id')
-
-      where('NOT EXISTS (?)', subquery)
-    end
-
     scope :with_knative_installed, -> { joins(:application_knative).merge(Clusters::Applications::Knative.available) }
 
     scope :preload_knative, -> {
@@ -161,16 +155,6 @@ module Clusters
       return platform_kubernetes if kubernetes?
     end
 
-    def all_projects
-      if project_type?
-        projects
-      elsif group_type?
-        first_group.all_projects
-      else
-        Project.none
-      end
-    end
-
     def first_project
       strong_memoize(:first_project) do
         projects.first
diff --git a/app/models/project.rb b/app/models/project.rb
index cca7da8c49a..8f234fba04f 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -415,12 +415,6 @@ class Project < ApplicationRecord
     .where(project_ci_cd_settings: { group_runners_enabled: true })
   end
 
-  scope :missing_kubernetes_namespace, -> (kubernetes_namespaces) do
-    subquery = kubernetes_namespaces.select('1').where('clusters_kubernetes_namespaces.project_id = projects.id')
-
-    where('NOT EXISTS (?)', subquery)
-  end
-
   enum auto_cancel_pending_pipelines: { disabled: 0, enabled: 1 }
 
   chronic_duration_attr :build_timeout_human_readable, :build_timeout,
diff --git a/spec/models/clusters/cluster_spec.rb b/spec/models/clusters/cluster_spec.rb
index 8f2f1b200e4..761695bfe91 100644
--- a/spec/models/clusters/cluster_spec.rb
+++ b/spec/models/clusters/cluster_spec.rb
@@ -121,26 +121,6 @@ describe Clusters::Cluster, :use_clean_rails_memory_store_caching do
     end
   end
 
-  describe '.missing_kubernetes_namespace' do
-    let!(:cluster) { create(:cluster, :provided_by_gcp, :project) }
-    let(:project) { cluster.project }
-    let(:kubernetes_namespaces) { project.kubernetes_namespaces }
-
-    subject do
-      described_class.joins(:projects).where(projects: { id: project.id }).missing_kubernetes_namespace(kubernetes_namespaces)
-    end
-
-    it { is_expected.to contain_exactly(cluster) }
-
-    context 'kubernetes namespace exists' do
-      before do
-        create(:cluster_kubernetes_namespace, project: project, cluster: cluster)
-      end
-
-      it { is_expected.to be_empty }
-    end
-  end
-
   describe 'validations' do
     subject { cluster.valid? }
 
@@ -423,31 +403,6 @@ describe Clusters::Cluster, :use_clean_rails_memory_store_caching do
     end
   end
 
-  describe '#all_projects' do
-    let(:project) { create(:project) }
-    let(:cluster) { create(:cluster, projects: [project]) }
-
-    subject { cluster.all_projects }
-
-    context 'project cluster' do
-      it 'returns project' do
-        is_expected.to eq([project])
-      end
-    end
-
-    context 'group cluster' do
-      let(:cluster) { create(:cluster, :group) }
-      let(:group) { cluster.group }
-      let(:project) { create(:project, group: group) }
-      let(:subgroup) { create(:group, parent: group) }
-      let(:subproject) { create(:project, group: subgroup) }
-
-      it 'returns all projects for group' do
-        is_expected.to contain_exactly(project, subproject)
-      end
-    end
-  end
-
   describe '#first_project' do
     subject { cluster.first_project }
 
diff --git a/spec/models/project_spec.rb b/spec/models/project_spec.rb
index 24dfd0c5605..32fb0c0ff73 100644
--- a/spec/models/project_spec.rb
+++ b/spec/models/project_spec.rb
@@ -173,24 +173,6 @@ describe Project do
     it { is_expected.to include_module(Sortable) }
   end
 
-  describe '.missing_kubernetes_namespace' do
-    let!(:project) { create(:project) }
-    let!(:cluster) { create(:cluster, :provided_by_user, :group) }
-    let(:kubernetes_namespaces) { project.kubernetes_namespaces }
-
-    subject { described_class.missing_kubernetes_namespace(kubernetes_namespaces) }
-
-    it { is_expected.to contain_exactly(project) }
-
-    context 'kubernetes namespace exists' do
-      before do
-        create(:cluster_kubernetes_namespace, project: project, cluster: cluster)
-      end
-
-      it { is_expected.to be_empty }
-    end
-  end
-
   describe 'validation' do
     let!(:project) { create(:project) }