On the morning of January 17 2017, seven months after the EU referendum, Theresa May said at Lancaster House: “We will pursue a bold and ambitious free trade agreement with the European Union. This agreement should allow for the freest possible trade in goods and services between Britain and the EU’s member states.”

Recognising what continued membership of the single market and customs union after Brexit would entail, she added that it “would mean complying with the EU’s rules and regulations... without having a vote on what those rules and regulations are... It would to all intents and purposes mean not leaving the EU at all”. Words echoed by Dominic Raab, when reflecting on the exit deal shortly to be voted on in Parliament.

So how did the Government lose its way? Historians will come to write the story of how Lancaster House morphed into present Government policy. It will be a story of the inflexibility of EU leaders, the botched 2017 general election, and the tin ear of British political leadership. By leaving most of the negotiations to civil servants, any semblance of political sensitivity was lost. And voices in Cabinet argued that business leaders wanted no change to the present customs arrangements without any regard to the advantages of leaving the customs union.