Michel Barnier, left, expressed outrage that Stephen Barclay had told him five times that the draft withdrawal agreement was dead

The EU warned Stephen Barclay that he was putting Britain in legal breach of the terms of the Brexit extension until October 31 during bad-tempered talks in Brussels last week.

Michel Barnier, the EU’s lead negotiator, expressed outrage that the Brexit secretary had told him five times that the draft withdrawal agreement was dead.

Mr Barnier told the cabinet minister that he was “backtracking” and “deviating” from a legal guarantee that government would not undermine the withdrawal agreement during the extension

“Barclay was told he was backtracking and in breach of the terms of the extension that was signed by Theresa May in April,” a diplomat briefed on the meeting said. “The terms of the extension is clear. It is for ratification not renegotiation or