Barnier takes apart May’s Chequers plan

Mrs May’s proposal for a “facilitated customs arrangement” opened up the risk of major fraud, additional bureaucracy and damage to EU businesses, he said.

Mr Barnier was speaking shortly after Mrs May issued a challenge to Brussels to “evolve” its negotiating position in response to the publication of her Brexit blueprint.

He said the EU had always been “creative and flexible” in its approach to negotiations.

But he insisted that future talks would be based on the guidelines issued by the European Council in March – which included the controversial proposal to keep Northern Ireland in the EU customs union – and not on Mrs May’s document.

“There will be a deal if there is an agreement on the backstop,” said Mr Barnier.

“It’s not necessarily our backstop. We can work on this, amend it, improve our backstop – the one that the Commission proposed on behalf of the Union.

“Technically we feel that it’s workable, we can improve it further, we can work on it. We are doing that work.

“But we need an operational backstop now, in the Withdrawal Agreement, and not later.”

Liberal Democrat Brexit spokesman Tom Brake said that Mrs May’s Chequers deal had been “diplomatically, but systematically, torn apart” by Mr Barnier.

“If this is what Barnier is saying in public, just imagine what the government are being told in private,” said Mr Brake.

“With serious issues yet to be resolved, not least at the border of Northern Ireland, the prospect of a catastrophic no-deal Brexit is becoming more concrete by the day. It is time the people were given the final say, and an opportunity to exit from Brexit.”

Labour MP Alex Sobel, a supporter of the Best for Britain campaign for a second referendum, said: “Barnier today has politely ripped apart the embattled prime minister’s plan only hours after she insisted there would be no further compromise on her side.

“I am not surprised that this cobbled together political deal completely fails to address the rules based order which means goods can flow freely throughout European Single Market.

“It is a total embarrassment that our prime minister is leading us off of a hard Brexit cliff edge by virtue signalling to hard line Brexiteers who would love nothing more than negotiations to fail and the UK to crash out of the single market with no deal.”

In her first major Brexit speech since the wave of ministerial resignations which followed her Chequers deal, the prime minister dinsisted her white paper proposals were “a significant development of our position… a coherent package”.

And she said: “It is now for the EU to respond – not simply to fall back on to previous positions which have already been proven unworkable, but to evolve their position in kind.

“And, on that basis, I look forward to resuming constructive discussions.”

Speaking in Belfast, Mrs May also took aim at critics from the increasingly strident Hard Brexit wing of the Conservative Party, accusing them of being ready to “betray” the people of Northern Ireland and the Republic.

She took on the argument of prominent Eurosceptics including Jacob Rees-Mogg, who say the UK should simply declare it will impose no checks on its side of the Irish border and leave it to Brussels to decide whether to require the Republic to erect barriers on the other.

“The protection of the peace process and upholding our binding commitments in the Belfast Agreement are grave responsibilities,” she said.

“Not to seek a solution would be to resume our career as an independent sovereign trading nation by betraying commitments to a part of our nation and to our nearest neighbour.”

And she took a swipe at former foreign secretary Boris Johnson’s claim – repeated in his resignation speech to the Commons on Wednesday – that technological solutions could be used to avoid the need for infrastructure at the border.

“No technology solution to address these issues has been designed yet or implemented anywhere in the world, let alone in such a unique and highly sensitive context as the Northern Ireland border,” she said.