diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3b623cdc..236386f8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## Unreleased
+
+* Replace inline style attributes in td/th elements with classes [#268](https://github.com/alphagov/govspeak/pull/268)
+
 ## 7.0.2
 
 * Fix for abbreviations nested in button. [#267](https://github.com/alphagov/govspeak/pull/267)
diff --git a/lib/govspeak/html_sanitizer.rb b/lib/govspeak/html_sanitizer.rb
index 9458f45e..de554a94 100644
--- a/lib/govspeak/html_sanitizer.rb
+++ b/lib/govspeak/html_sanitizer.rb
@@ -69,6 +69,8 @@ def sanitize_config(allowed_elements: [])
         "svg" => Sanitize::Config::RELAXED[:attributes][:all] + %w[xmlns width height viewbox focusable],
         "path" => Sanitize::Config::RELAXED[:attributes][:all] + %w[fill d],
         "div" => [:data],
+        # @TODO  These style attributes can be removed once we've checked there
+        # isn't hardcoded HTML in documents that uses them
         "th" => Sanitize::Config::RELAXED[:attributes]["th"] + %w[style],
         "td" => Sanitize::Config::RELAXED[:attributes]["td"] + %w[style],
         "govspeak-embed-attachment" => %w[content-id],
diff --git a/lib/govspeak/post_processor.rb b/lib/govspeak/post_processor.rb
index 26f5cfbd..d6178711 100644
--- a/lib/govspeak/post_processor.rb
+++ b/lib/govspeak/post_processor.rb
@@ -102,6 +102,23 @@ def self.extension(title, &block)
       end
     end
 
+    extension("convert table cell inline styles to classes") do |document|
+      document.css("th[style], td[style]").each do |el|
+        style = el.remove_attribute("style")
+        matches = style.value.scan(/text-align:\s*(left|center|right)/).flatten
+
+        next unless matches.any?
+
+        class_name = "cell-text-#{matches.last}"
+
+        if el[:class]
+          el[:class] += " #{class_name}"
+        else
+          el[:class] = class_name
+        end
+      end
+    end
+
     extension("use gem component for buttons") do |document|
       document.css(".govuk-button").map do |el|
         button_html = GovukPublishingComponents.render(
diff --git a/test/govspeak_table_with_headers_test.rb b/test/govspeak_table_with_headers_test.rb
index 61bdb990..539b046b 100644
--- a/test/govspeak_table_with_headers_test.rb
+++ b/test/govspeak_table_with_headers_test.rb
@@ -58,21 +58,21 @@ def expected_outcome_for_table_with_alignments
 <table>
   <thead>
     <tr>
-      <td style="text-align: left"></td>
-      <th style="text-align: center" scope="col">Second Column</th>
-      <th style="text-align: right" scope="col">Third Column</th>
+      <td class="cell-text-left"></td>
+      <th scope="col" class="cell-text-center">Second Column</th>
+      <th scope="col" class="cell-text-right">Third Column</th>
     </tr>
   </thead>
   <tbody>
     <tr>
-      <th style="text-align: left" scope="row">First row</th>
-      <td style="text-align: center">Cell</td>
-      <td style="text-align: right">Cell</td>
+      <th scope="row" class="cell-text-left">First row</th>
+      <td class="cell-text-center">Cell</td>
+      <td class="cell-text-right">Cell</td>
     </tr>
     <tr>
-      <th style="text-align: left" scope="row">Second row</th>
-      <td style="text-align: center">Cell</td>
-      <td style="text-align: right">Cell</td>
+      <th scope="row" class="cell-text-left">Second row</th>
+      <td class="cell-text-center">Cell</td>
+      <td class="cell-text-right">Cell</td>
     </tr>
   </tbody>
 </table>
@@ -255,7 +255,7 @@ def document_body_with_table_headers_containing_links
     assert_equal document_body_with_hashes_for_row_headers.to_html, expected_outcome
   end
 
-  test "Cells are aligned correctly" do
+  test "Cells are given classes to indicate alignment" do
     assert_equal document_body_with_alignments.to_html, expected_outcome_for_table_with_alignments
   end