Brexit deal: Arlene Foster demands Boris Johnson meeting over fears he will cut Northern Ireland loose from UK

DUP leader arrives in London condemning any move towards 'break-up of the UK', in further headache for prime minister

Arlene Foster is meeting Boris Johnson amid growing Unionist fears that he will cut Northern Ireland loose in his desperation for a Brexit deal.

The leader of the Democratic Unionist party condemned any move towards “the break-up of the UK”, adding: “That’s not something that any prime minister in the UK is going to go along with.”

The meeting comes as Ireland's EU commissioner Phil Hogan claimed that "the penny is finally dropping" in London on the need for compromise on the controversial backstop.

The DUP fears Mr Johnson is poised to sidestep the central obstacle to a deal with Brussels by agreeing a backstop for Northern Ireland only – allowing Britain to escape the customs union and single market rules.

The EU agreed such a proposal two years ago, before Ms Foster forced Theresa May to stamp on it in the first of many humiliations for the former prime minister.

The DUP leader has branded a Northern-Ireland only backstop “anti-democratic and unconstitutional”, leaving Ulster “subject to EU rules without any means of changing them”.

But Mr Hogan suggested that Brussels has detected signs of a new readiness from the PM to discuss a solution which would treat Northern Ireland differently from the rest of the UK.

“Mr Johnson has made a proposal in the last few days talking about an all-Ireland food zone,” Hogan told The Irish Times. “That is certainly a clear indication of divergence between Northern Ireland and the Republic of Ireland, the EU and the rest of the UK. This is the first time that this has been spoken about by a British prime minister where they are prepared to accept some level of divergence between Northern Ireland and the rest of the UK.

“If we can build on that we certainly might get closer to one another in terms of a possible outcome."

Mr Hogan said a separate arrangement for Northern Ireland "would have to include all goods" and not just agricultural produce.

But he made clear Dublin was ready to talk about the idea, saying: "The Taoiseach has indicated in the last 24 hours that the Northern Ireland-only backstop is quite an interesting idea to revisit.”

Speaking before flying to London, Ms Foster said: “What we are focused on is getting a deal that works for the whole of the United Kingdom and works for Northern Ireland, and doesn’t have Northern Ireland hived off into a different customs union than the rest of the UK and breaking up the single market of the UK.

“That would be unheard-of and to think that any UK prime minister would be involved in that sort of thing would be an anathema. Jeremy Corbyn has said that in the past and our own prime minister has said that.

“I think what we they talking about is not delivering Brexit – what they are talking about is the break-up of the UK. That’s not something that any prime minister in the UK is going to, in any conscience, go along with.”

The warning comes after the prime minister softened his stance on demanding the full scrapping of the backstop, at a press conference in Dublin on Monday.

Instead, he hinted at a rewriting of the protocol – which is designed to avoid the return of border posts or checks – “while giving Ireland the assurance that it needs”.

The prime minister has already backed an all-Ireland arrangement for food and agriculture, widely seen as a major step in the direction of a Northern Ireland-only backstop.

Some observers believe Mr Johnson might be willing to sacrifice the DUP, which proposed Ms May up in power, now he has lost his Commons majority anyway and is demanding a general election.

However, he would still face huge obstacles to getting such a deal through the Commons, with many Tory MPs certain to oppose the danger to the Union.

Labour still would not back such an agreement, because it would fail to deliver frictionless trade for the rest of the UK – and would leave Mr Johnson free to slash regulations.

The prime minister’s spokesman said Mr Johnson would meet Ms Foster later today and insisted: “We are not seeking a Northern Ireland-only backstop.”