As the two leaders prepared to hold their first face-to-face meeting in Paris, Mr Macron once again dismissed the prime minister's repeated demands to reopen the withdrawal agreement as "not an option".

In highly-critical remarks on the eve of talks, the French president also said the UK would be the "main victim" of a hard Brexit, as he warned the cost would not be offset by a trade deal with the United States.

"Even if it were a strategic choice it would be at the cost of a historic vassalisation of the British state," Mr Macron said. "I don't think that is what Boris Johnson wants."

Rejecting accusations the bloc would be at fault for a no-deal Brexit, he continued: "It will be the responsibility of the British government, always.

"Firstly it was the British people that decided Brexit, and the British government has the possibility up to the last second to revoke Article 50."
The frank comments from Mr Macron could overshadow Mr Johnson's first meeting in Paris as prime minister, as the pair meet for a working lunch to discuss the current state of Britain's exit from the EU.

On Wednesday, Mr Johnson agreed with the German chancellor Angela Merkel that the "onus" was on his administration to set out a solution to the contentious Irish backstop policy within 30 days.

In press conference with the German leader, the prime minister said: "You have set a very blistering timetable of 30 days – if I understood you correctly, I am more than happy with that".

Ms Merkel, along with all other EU leaders, has said the withdrawal agreement cannot be reopened and that any solution has to be found in the future relationship.
“The backstop has always been a fall-back option until this issue is solved and one knows how one wants to do that,” Ms Merkel said

“It was said we will probably find a solution in two years. But we could also find one in the next 30 days, why not?”

Mr Johnson told Ms Merkel that the backstop would have to go as part of further discussions - or else Britain was prepared to leave without a deal. He said the backstop would need to be removed "whole and entire" before a deal could be reached.

But his remarks also came as Jeremy Corbyn wrote to other opposition leaders at Westminster, inviting them to a meeting in his office next week to discuss averting a no-deal Brexit.

In a letter, the Labour leader said: "The country is heading into a constitutional and political storm, so it is vital that we meet urgently, before Parliament returns.

"The chaos and dislocation of Boris Johnson's no-deal Brexit is real and threatening, as the Government's leaked Operation Yellowhammer dossier makes crystal clear. That's why we must do everything we can to stop it."