The note – marked ‘not for general distribution’ and obtained by BrexitCentral – is dated 26th November and states that the UK-EU customs union which would come into effect if the backstop is triggered “would be a practical barrier to the UK entering separate trade agreements on goods with third countries”.

This is in direct contradiction to the Prime Minister who has insisted that her deal will allow the UK to have an entirely independent trade policy. Indeed, she told the House of Commons just last Monday how “for the first time in 40 years, the UK will be able to strike new trade deals and open up new markets for our goods and services”.