The UK’s full CPTPP membership took effect on Tuesday, 1 September, giving Britain access to the 11-nation trading bloc after Canada ratified the accession in July. The move has been sold as a trade gain for the UK, but Andy Burnham has been warned that the benefit will not come close to covering the losses tied to Brexit and leaving the EU single market.
The headline figure attached to the change is £2bn a year. Mike Galsworthy, chair of European Movement UK, said: “While £2 bn a year isn't to be sniffed at, even if it only reaches that figure after about 15 years, what it doesn't do is plug the Brexit black hole. The OBR still scores leaving the single market at 4 per cent GDP, roughly £120 bn a year. That's sixty times bigger.”
Canada ratified in July
Britain initially signed up to the CPTPP under Rishi Sunak’s government in 2023, with implementation of Britain’s entry commencing the next year. Canada served as the final member of the bloc to sanction the UK’s participation, making the July ratification the last step before full membership could take effect on Tuesday, 1 September.
That sequence matters because the UK is not joining a blank slate. Mike Galsworthy said Britain already had trade deals with nine of the eleven members, and said most of those deals were inherited from agreements the EU negotiated. The practical effect is that the new access adds scope, but not a wholesale rewrite of Britain’s trade map.
European Movement UK criticism
Joshua Reynolds, the Liberal Democrat trade spokesperson, sharpened that point. “This deal is simply no replacement for trade with our closest and largest partners in Europe,” he said. “If the Government are serious about real economic growth, they must stop pretending far-flung trade agreements will fix the problem and focus on re-joining the customs union, and crucially re-entering the Single Market.”
The row comes amid concerns that Andy Burnham has said he will stick to Keir Starmer’s red lines, including not rejoining the EU, Single Market or Customs Union and not looking at free movement again. For readers tracking trade policy, the unresolved issue is not whether Britain has entered the CPTPP, but how much of the promised £2bn will arrive in practice and over what period, against a reported £11.7bn a year loss from leaving the EU.
Britain’s trade arithmetic
Naomi Smith of Best for Britain is among the figures pushing back against the idea that the CPTPP can offset the wider economic damage from Brexit. The comparison now sits at the centre of the debate: a new Pacific-facing trading link on one side, and a much larger loss in Europe-facing trade on the other.
