A leaked draft legal analysis produced by the House of Commons library warns that the UK will face “a practical barrier” to striking a trade deal with the US or other non-EU countries if the country falls into the backstop customs arrangements.
The remarks, contained within a draft paper that leaked on Monday morning, emerged hours before the attorney general, Geoffrey Cox, was scheduled to brief the Commons about his advice on the Brexit deal negotiated by May.
The 27-page document, dated 26 November, says the UK would conform to EU customs rules if it entered the backstop, and adds that this “would be a practical barrier to the UK entering separate trade agreements on goods with third countries”.
The Northern Ireland backstop has become the most controversial part of the legally binding withdrawal agreement struck by May with the European Union, because it ties the UK to EU rules in order to maintain an open border in Ireland if no free trade agreement has been signed.
However, during the G20 summit over the weekend, May said the US president was wrong. She said: “I’m very happy to tell President Trump and others that we will have an independent trade policy, we will be able to do trade deals.”