David Davis’ influence over the Brexit negotiations has waned as talks with Brussels have dragged on and the former SAS reservist now faces a fresh challenge to his diminished territory.

The Brexit Secretary has been left bruised and battered after his quixotic stand-off with Theresa May over the terms of Britain’s offer to keep the UK aligned with EU customs rules as a backstop to prevent the return of a hard border between Ireland and Northern Ireland.

His clash with the prime minister, in which he threatened to resign unless the backstop had a clear end-date, left both wounded on Thursday and he faced a fresh blow to his pride in a hurried, low-key meeting with Michel Barnier in Brussels on Monday.

Rather than smiling photos or press briefings, Mr Davis was whisked in and out of the back of the European Commission headquarters for what was a frustrating, fruitless meeting.

Mr Davis was keen to push the EU to accelerate talks on the "political declaration", which is a non-binding paper due to accompany the legally-binding Brexit withdrawal agreement that sets out the framework of the yet-to be negotiated free trade deal with Britain.

In truth, Mr Davis had little else to discuss. The customs paper published after his ultimatum was not his work but that of Olly Robbins, Theresa May’s Brexit “sherpa”.