Andy Burnham has been warned that the UK's full entry into the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), which took effect on 1 September, will not offset the trade losses caused by Brexit, despite delivering an estimated £2bn boost to the economy. The warning comes after The Independent revealed last week that the UK loses £11.7bn a year in trade as a result of leaving the EU, with campaigners arguing the CPTPP gains are dwarfed by this shortfall and by the wider economic damage from exiting the Single Market.

The CPTPP became fully operational after Canada, the last of the 11-nation bloc's members, ratified UK accession in July, following the deal's initial signing under Rishi Sunak in 2023. Critics, including European Movement UK chair Mike Galsworthy and Best for Britain's Naomi Smith, note the Office for Budget Responsibility puts the cost of leaving the Single Market at around 4 per cent of GDP, roughly £120bn a year — sixty times the CPTPP's projected benefit — and that the UK already had trade deals with nine of the eleven CPTPP members. Liberal Democrat trade spokesperson Joshua Reynolds called for rejoining the customs union and Single Market instead, while the row highlights pressure on Burnham, who has said he will maintain Keir Starmer's red lines against rejoining the EU, Single Market or Customs Union.