diff --git a/Gemfile b/Gemfile
index 2c2b7eb089c..c5361add5cd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,6 +10,7 @@ gem "bootsnap", require: false
 gem "carrierwave"
 gem "carrierwave-i18n"
 gem "chronic"
+gem "content_block_tools"
 gem "dalli"
 gem "dartsass-rails"
 gem "diffy"
diff --git a/Gemfile.lock b/Gemfile.lock
index 400ee884212..5c770aa0b55 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -139,6 +139,8 @@ GEM
     coderay (1.1.3)
     concurrent-ruby (1.3.4)
     connection_pool (2.4.1)
+    content_block_tools (0.3.0)
+      actionview (>= 6, < 7.2.2)
     crack (1.0.0)
       bigdecimal
       rexml
@@ -1028,6 +1030,7 @@ DEPENDENCIES
   carrierwave-i18n
   chronic
   climate_control
+  content_block_tools
   cucumber
   cucumber-rails
   dalli
diff --git a/app/helpers/admin/admin_govspeak_helper.rb b/app/helpers/admin/admin_govspeak_helper.rb
index 5448f0add25..157d1777aed 100644
--- a/app/helpers/admin/admin_govspeak_helper.rb
+++ b/app/helpers/admin/admin_govspeak_helper.rb
@@ -4,7 +4,8 @@ module Admin::AdminGovspeakHelper
   def govspeak_to_admin_html(govspeak, images = [], attachments = [], alternative_format_contact_email = nil)
     images = prepare_images(images)
     attachments = prepare_attachments(attachments, alternative_format_contact_email)
-    wrapped_in_govspeak_div(bare_govspeak_to_admin_html(govspeak, images, attachments))
+    html = ContentBlockManager::FindAndReplaceEmbedCodesService.call bare_govspeak_to_admin_html(govspeak, images, attachments)
+    wrapped_in_govspeak_div(html)
   end
 
   def govspeak_edition_to_admin_html(edition)
diff --git a/lib/engines/content_block_manager/app/models/content_block_manager/content_block/edition.rb b/lib/engines/content_block_manager/app/models/content_block_manager/content_block/edition.rb
index 11840ae093a..e2143dc6f64 100644
--- a/lib/engines/content_block_manager/app/models/content_block_manager/content_block/edition.rb
+++ b/lib/engines/content_block_manager/app/models/content_block_manager/content_block/edition.rb
@@ -8,9 +8,24 @@ class Edition < ApplicationRecord
       include ValidatesDetails
       include Workflow
 
+      scope :current_versions, lambda {
+        joins(
+          "LEFT JOIN content_block_documents document ON document.latest_edition_id = content_block_editions.id",
+        ).where(state: "published")
+      }
+
       def update_document_reference_to_latest_edition!
         document.update!(latest_edition_id: id)
       end
+
+      def render
+        ContentBlockTools::ContentBlock.new(
+          document_type: "content_block_#{block_type}",
+          content_id: document.content_id,
+          title:,
+          details:,
+        ).render
+      end
     end
   end
 end
diff --git a/lib/engines/content_block_manager/app/services/content_block_manager/find_and_replace_embed_codes_service.rb b/lib/engines/content_block_manager/app/services/content_block_manager/find_and_replace_embed_codes_service.rb
new file mode 100644
index 00000000000..62d91a0f014
--- /dev/null
+++ b/lib/engines/content_block_manager/app/services/content_block_manager/find_and_replace_embed_codes_service.rb
@@ -0,0 +1,35 @@
+module ContentBlockManager
+  class FindAndReplaceEmbedCodesService
+    def self.call(html)
+      new(html).call
+    end
+
+    def call
+      embed_content_references.each do |reference|
+        content_block = content_blocks.find { |c| c.document.content_id == reference.content_id }
+        next if content_block.nil?
+
+        html.gsub!(reference.embed_code, content_block.render)
+      end
+
+      html
+    end
+
+  private
+
+    attr_reader :html
+
+    def initialize(html)
+      @html = html
+    end
+
+    def embed_content_references
+      @embed_content_references ||= ContentBlockTools::ContentBlockReference.find_all_in_document(html)
+    end
+
+    def content_blocks
+      @content_blocks ||= ContentBlockManager::ContentBlock::Edition.current_versions
+      .where(document: { content_id: embed_content_references.map(&:content_id) })
+    end
+  end
+end
diff --git a/lib/engines/content_block_manager/test/unit/app/models/content_block_edition_test.rb b/lib/engines/content_block_manager/test/unit/app/models/content_block_edition_test.rb
index f99d41c018a..ed0bb2ad40e 100644
--- a/lib/engines/content_block_manager/test/unit/app/models/content_block_edition_test.rb
+++ b/lib/engines/content_block_manager/test/unit/app/models/content_block_edition_test.rb
@@ -1,122 +1,161 @@
 require "test_helper"
 
 class ContentBlockManager::ContentBlockEditionTest < ActiveSupport::TestCase
-  setup do
-    @new_content_id = SecureRandom.uuid
-    ContentBlockManager::ContentBlock::Edition.any_instance.stubs(:create_random_id).returns(@new_content_id)
-
-    @created_at = Time.zone.local(2000, 12, 31, 23, 59, 59).utc
-    @updated_at = Time.zone.local(2000, 12, 31, 23, 59, 59).utc
-    @details = { "some_field" => "some_content" }
-    @title = "Document title"
-    @creator = create(:user)
-    @organisation = create(:organisation)
-
-    @content_block_edition = ContentBlockManager::ContentBlock::Edition.new(
-      created_at: @created_at,
-      updated_at: @updated_at,
-      details: @details,
+  extend Minitest::Spec::DSL
+
+  let(:new_content_id) { SecureRandom.uuid }
+
+  let(:created_at) { Time.zone.local(2000, 12, 31, 23, 59, 59).utc }
+  let(:updated_at) { Time.zone.local(2000, 12, 31, 23, 59, 59).utc }
+  let(:details) { { "some_field" => "some_content" } }
+  let(:title) { "Document title" }
+  let(:creator) { create(:user) }
+  let(:organisation) { create(:organisation) }
+
+  let(:content_block_edition) do
+    ContentBlockManager::ContentBlock::Edition.new(
+      created_at:,
+      updated_at:,
+      details:,
       document_attributes: {
         block_type: "email_address",
-        title: @title,
+        title:,
       },
-      creator: @creator,
-      organisation_id: @organisation.id.to_s,
+      creator:,
+      organisation_id: organisation.id.to_s,
     )
-    @content_block_edition.stubs(:schema).returns(build(:content_block_schema))
   end
 
-  test "content_block_edition exists with required data" do
-    @content_block_edition.save!
-    @content_block_edition.reload
+  before do
+    ContentBlockManager::ContentBlock::Edition.any_instance.stubs(:create_random_id).returns(new_content_id)
+    content_block_edition.stubs(:schema).returns(build(:content_block_schema))
+  end
+
+  it "exists with required data" do
+    content_block_edition.save!
+    content_block_edition.reload
 
-    assert_equal @created_at, @content_block_edition.created_at
-    assert_equal @updated_at, @content_block_edition.updated_at
-    assert_equal @details, @content_block_edition.details
+    assert_equal created_at, content_block_edition.created_at
+    assert_equal updated_at, content_block_edition.updated_at
+    assert_equal details, content_block_edition.details
   end
 
-  test "it persists the block type to the document" do
-    @content_block_edition.save!
-    @content_block_edition.reload
-    document = @content_block_edition.document
+  it "persists the block type to the document" do
+    content_block_edition.save!
+    content_block_edition.reload
+    document = content_block_edition.document
 
-    assert_equal document.block_type, @content_block_edition.block_type
+    assert_equal document.block_type, content_block_edition.block_type
   end
 
-  test "it persists the title to the document" do
-    @content_block_edition.save!
-    @content_block_edition.reload
-    document = @content_block_edition.document
+  it "persists the title to the document" do
+    content_block_edition.save!
+    content_block_edition.reload
+    document = content_block_edition.document
 
-    assert_equal document.title, @content_block_edition.title
+    assert_equal document.title, content_block_edition.title
   end
 
-  test "it creates a document" do
-    @content_block_edition.save!
-    @content_block_edition.reload
+  it "creates a document" do
+    content_block_edition.save!
+    content_block_edition.reload
 
-    assert_not_nil @content_block_edition.document
-    assert_equal @content_block_edition.document.content_id, @new_content_id
+    assert_not_nil content_block_edition.document
+    assert_equal content_block_edition.document.content_id, new_content_id
   end
 
-  test "it adds a content id if a document is provided" do
-    @content_block_edition.document = build(:content_block_document, :email_address, content_id: nil)
-    @content_block_edition.save!
-    @content_block_edition.reload
+  it "adds a content id if a document is provided" do
+    content_block_edition.document = build(:content_block_document, :email_address, content_id: nil)
+    content_block_edition.save!
+    content_block_edition.reload
 
-    assert_not_nil @content_block_edition.document
-    assert_equal @content_block_edition.document.content_id, @new_content_id
+    assert_not_nil content_block_edition.document
+    assert_equal content_block_edition.document.content_id, new_content_id
   end
 
-  test "it validates the presence of a document block_type" do
-    @content_block_edition = build(
+  it "validates the presence of a document block_type" do
+    content_block_edition = build(
       :content_block_edition,
-      created_at: @created_at,
-      updated_at: @updated_at,
-      details: @details,
+      created_at:,
+      updated_at:,
+      details:,
       document_attributes: {
         block_type: nil,
       },
-      organisation_id: @organisation.id.to_s,
+      organisation_id: organisation.id.to_s,
     )
 
-    assert_invalid @content_block_edition
-    assert @content_block_edition.errors.full_messages.include?("Document block type can't be blank")
+    assert_invalid content_block_edition
+    assert content_block_edition.errors.full_messages.include?("Document block type can't be blank")
   end
 
-  test "it validates the presence of a document title" do
+  it "validates the presence of a document title" do
     content_block_edition = build(
       :content_block_edition,
-      created_at: @created_at,
-      updated_at: @updated_at,
-      details: @details,
+      created_at:,
+      updated_at:,
+      details:,
       document_attributes: {
         title: nil,
       },
-      organisation_id: @organisation.id.to_s,
+      organisation_id: organisation.id.to_s,
     )
 
     assert_invalid content_block_edition
     assert content_block_edition.errors.full_messages.include?("Title can't be blank")
   end
 
-  test "it adds a creator and first edition author for new records" do
-    @content_block_edition.save!
-    @content_block_edition.reload
-    assert_equal @content_block_edition.creator, @content_block_edition.edition_authors.first.user
+  it "adds a creator and first edition author for new records" do
+    content_block_edition.save!
+    content_block_edition.reload
+    assert_equal content_block_edition.creator, content_block_edition.edition_authors.first.user
+  end
+
+  describe "#creator=" do
+    it "raises an exception if called for a persisted record" do
+      content_block_edition.save!
+      assert_raise RuntimeError do
+        content_block_edition.creator = create(:user)
+      end
+    end
   end
 
-  test "#creator= raises an exception if called for a persisted record" do
-    @content_block_edition.save!
-    assert_raise RuntimeError do
-      @content_block_edition.creator = create(:user)
+  describe "#update_document_reference_to_latest_edition!" do
+    it "updates the document reference to the latest edition" do
+      latest_edition = create(:content_block_edition, document: content_block_edition.document)
+      latest_edition.update_document_reference_to_latest_edition!
+
+      assert_equal latest_edition.document.latest_edition_id, latest_edition.id
     end
   end
 
-  test "#update_document_reference_to_latest_edition! updates the document reference to the latest edition" do
-    latest_edition = create(:content_block_edition, document: @content_block_edition.document)
-    latest_edition.update_document_reference_to_latest_edition!
+  describe ".current_versions" do
+    it "returns current published versions" do
+      document = create(:content_block_document, :email_address)
+      edition = create(:content_block_edition, :email_address, state: "published", document:)
+      draft_edition = create(:content_block_edition, :email_address, state: "draft", document:)
+      document.latest_edition = draft_edition
+      document.save!
+
+      assert_equal ContentBlockManager::ContentBlock::Edition.current_versions.to_a, [edition]
+    end
+  end
 
-    assert_equal latest_edition.document.latest_edition_id, latest_edition.id
+  describe "#render" do
+    let(:rendered_response) { "RENDERED" }
+    let(:stub_block) { stub("ContentBlockTools::ContentBlock", render: rendered_response) }
+    let(:document) { content_block_edition.document }
+
+    it "initializes and renders a content block" do
+      ContentBlockTools::ContentBlock.expects(:new)
+                                     .with(
+                                       document_type: "content_block_#{document.block_type}",
+                                       content_id: document.content_id,
+                                       title:,
+                                       details:,
+                                     ).returns(stub_block)
+
+      assert_equal content_block_edition.render, rendered_response
+    end
   end
 end
diff --git a/lib/engines/content_block_manager/test/unit/app/services/find_and_replace_embed_codes_service_test.rb b/lib/engines/content_block_manager/test/unit/app/services/find_and_replace_embed_codes_service_test.rb
new file mode 100644
index 00000000000..7ba41253ed0
--- /dev/null
+++ b/lib/engines/content_block_manager/test/unit/app/services/find_and_replace_embed_codes_service_test.rb
@@ -0,0 +1,51 @@
+require "test_helper"
+
+class ContentBlockManager::FindAndReplaceEmbedCodesServiceTest < ActiveSupport::TestCase
+  extend Minitest::Spec::DSL
+
+  it "finds and replaces embed codes" do
+    document_1 = create(:content_block_document, :email_address)
+    edition_1 = create(:content_block_edition, :email_address, state: "published", document: document_1)
+    document_1.latest_edition = edition_1
+    document_1.save!
+
+    document_2 = create(:content_block_document, :email_address)
+    edition_2 = create(:content_block_edition, :email_address, state: "published", document: document_2)
+    document_2.latest_edition = edition_2
+    document_2.save!
+
+    html = """
+      <p>Hello there</p>
+      <p>#{edition_2.document.embed_code}</p>
+      <p>#{edition_1.document.embed_code}</p>
+    """
+
+    expected = """
+      <p>Hello there</p>
+      <p>#{edition_2.render}</p>
+      <p>#{edition_1.render}</p>
+    """
+
+    result = ContentBlockManager::FindAndReplaceEmbedCodesService.call(html)
+
+    assert_equal result, expected
+  end
+
+  it "ignores blocks that aren't present in the database" do
+    edition = build(:content_block_edition, :email_address)
+
+    html = edition.document.embed_code
+
+    result = ContentBlockManager::FindAndReplaceEmbedCodesService.call(html)
+    assert_equal result, html
+  end
+
+  it "ignores blocks that don't have a live version" do
+    edition = create(:content_block_edition, :email_address, state: "draft")
+
+    html = edition.document.embed_code
+
+    result = ContentBlockManager::FindAndReplaceEmbedCodesService.call(html)
+    assert_equal result, html
+  end
+end
diff --git a/test/unit/app/helpers/admin/admin_govspeak_helper_test.rb b/test/unit/app/helpers/admin/admin_govspeak_helper_test.rb
index a10cc0f0cd2..d19fa13e428 100644
--- a/test/unit/app/helpers/admin/admin_govspeak_helper_test.rb
+++ b/test/unit/app/helpers/admin/admin_govspeak_helper_test.rb
@@ -121,4 +121,14 @@ class Admin::AdminGovspeakHelperTest < ActionView::TestCase
       assert_equivalent_html "<div class=\"govspeak\">#{contact_html}</div>", govspeak_to_admin_html(input)
     end
   end
+
+  test "should call the embed codes helper" do
+    input = "Here is some Govspeak"
+    expected = "Expected output"
+    ContentBlockManager::FindAndReplaceEmbedCodesService.expects(:call).with(
+      bare_govspeak_to_admin_html(input, [], []),
+    ).returns(expected)
+
+    assert_equivalent_html "<div class=\"govspeak\">#{expected}</div>", govspeak_to_admin_html(input)
+  end
 end