The viability of the British government's latest proposal for a new post-Brexit free trade arrangement with the EU has been called into question by a key EU adviser.

During her most recent Brexit speech, UK prime minister Theresa May indicated that she would be looking to establish a new trade relationship with the EU based on mutual recognition of standards, overseen by a third-party court made up of nominees from both sides.

This plan is intended to ensure shared regulatory outcomes between both regions, giving the UK access to the European single market while also maintaining a degree of independence from it. However, Stefaan de Rynck - the main advisor to the EU's chief Brexit negotiator Michel Barnier - has subsequently suggested that such a plan may not be achievable.

During a special LSE lecture in London, he indicated that Mrs May's plans are likely to be regarded by the EU as a move that would undermine the integrity of the single market and the autonomy of the bloc's remaining nations.

Mr de Rynck said: "The EU has moved away in the wake of the financial crisis from mutual recognition of national standards to a centralized approach, with a single EU rule book and common enforcement structures and single supervisory structures.

"If you are in a very integrated market but you don't have the joint enforcement structures, then you can see the potential for all kinds of difficulties."

During the talk, Mr de Rynck also warned the British government that EU businesses would prioritize maintaining the integrity of the EU single market over preserving access to British markets, suggesting that it may be difficult to secure the kind of compromise deals that Mrs May is seeking.