The leader of the DUP is holding “wide-ranging” meetings with EU officials in Brussels over the next few days in a bid to break the Brexit deadlock ahead of a looming no-deal deadline.

Arlene Foster flew in from Belfast in the early hours of Tuesday morning and met with chief negotiator Michel Barnier and other officials, as well as representatives from member states.

The right-wing party, which is propping up Theresa May’s minority government in Parliament, is seen as key to a deal on the Northern Ireland border – and has therefore been granted huge access in the EU capital.

Critics of the government said Ms Foster had effectively “taken over” Brexit negotiations from Theresa May – as she prepared to meet representatives of member states, negotiators, officials, and top EU parliament figures.

“We have a very wide range of meetings within the Commission, we’ve just come from a meeting with Mr Barnier,” Diane Dodds, the DUP’s MEP who is accompanying Ms Foster on the trip, told reporters on Tuesday afternoon.

Speaking at the same press conference Ms Foster accused the EU of not understanding British unionism with its plans to solve the Northern Irish border.

“It is vital that the EU from their perspective understands the sensitivities around Northern Ireland and that we’re going to be the only part of the United Kingdom with a land border with the EU after we leave next year,” she said.

It is vital that the EU from their perspective understands the sensitivities around Northern Ireland Arlene Foster, DUP leader

The party leader added that she would not accept any checks between Great Britain and Northern Ireland, rejecting the EU’s bid to “de-dramatise” them.

She has in recent days appeared to shoot down a nascent bid by the British government to compromise on checks across the Irish sea, describing her red-lines as “blood red”. An EU bid to compromise by having checks done in advance appeared not to impress the Ms Foster either.

“Our own government was very clear, and we reiterated the issue last week with the prime minister that there cannot be any customs or regulatory barriers between ourselves and the rest of the United Kingdom – both ways,” she said.

“It’s not just a case of regulations between Northern Ireland and Great Britain, it’s also between Great Britain and Northern Ireland. I think that’s very clear, we’ve made that very clear.”

The DUP almost certainly has the power to sink any deal signed by the government because Theresa May threw away her parliamentary majority in a snap general election last year, and now relies on DUP MPs to pass legislation with a confidence-and-supply arrangement.

Though EU sources in Brussels have been optimistic about a deal, Downing Street yesterday suggested caution.

British officials will be in town this week for back-room discussions as the two sides hope to secure some kind of progress before a European Council summit next week, which will be attended by Theresa May and the EU27 leaders.

Labour MP David Lammy, a supporter of the Best for Britain campaign, said: “Arlene Foster is not an MP and not even first minister but she holds the trump card in these negotiations.

Brexit threatens life on the Irish border: in pictures Show all 15 1 /15 Brexit threatens life on the Irish border: in pictures Brexit threatens life on the Irish border: in pictures An abandoned shop is seen in Mullan, Co Monaghan. The building was home to four families who left during the Troubles. The town was largely abandoned after the hard border was put in place during the conflict. Mullan has seen some regeneration in recent years, but faces an uncertain future with Brexit on the horizon Reuters Brexit threatens life on the Irish border: in pictures A defaced ‘Welcome to Northern Ireland’ sign stands on the border in Middletown, Co Armagh Reuters Brexit threatens life on the Irish border: in pictures Mervyn Johnson owns a garage in the border town of Pettigo, which straddles the counties of Donegal and Fermanagh. ‘I’ve been here since 1956, it was a bit of a problem for a few years. My premises has been blown up about six or seven times, we just kept building and starting again,’ Johnson said laughing. ‘We just got used to it [the hard border] really but now that it’s gone, we wouldn't like it back again’ Reuters Brexit threatens life on the Irish border: in pictures Farmer Gordon Crockett’s Coshquin farm straddles both Derry/Londonderry in the North and Donegal in the Republic. ‘At the minute there is no real problem, you can cross the border as free as you want. We could cross it six or eight times a day,’ said Crockett. ‘If there was any sort of obstruction it would slow down our work every day’ Reuters Brexit threatens life on the Irish border: in pictures John Murphy flies the European flag outside his home near the border village of Forkhill, Co Armagh Reuters Brexit threatens life on the Irish border: in pictures Potter Brenda McGinn stands outside her Mullan, Co Monaghan, studio – the former Jas Boylan shoe factory which was the main employer in the area until it shut down due to the Troubles. ‘When I came back, this would have been somewhere you would have driven through and have been quite sad. It was a decrepit looking village,’ said McGinn, whose Busy Bee Ceramics is one of a handful of enterprises restoring life to the community. ‘Now this is a revitalised, old hidden village’ Reuters Brexit threatens life on the Irish border: in pictures Union Flag colours painted on kerbstones and bus-stops along the border village of Newbuildings, Co Derry/Londonderry Reuters Brexit threatens life on the Irish border: in pictures Grass reflected in Lattone Lough, which is split by the border between Cavan and Fermanagh, seen from near Ballinacor, Northern Ireland Reuters Brexit threatens life on the Irish border: in pictures Donegalman David McClintock sits in the Border Cafe in the village of Muff, which straddles Donegal and Derry/Londonderry Reuters Brexit threatens life on the Irish border: in pictures An old Irish phone box stands alongside a bus stop in the border town of Glaslough, Co Monaghan Reuters Brexit threatens life on the Irish border: in pictures Billboards are viewed from inside a disused customs hut in Carrickcarnon, Co Down, on the border with Co Louth in the Republic Reuters Brexit threatens life on the Irish border: in pictures Seamus McQuaid takes packages that locals on the Irish side of the border have delivered to his business, McQuaid Auto-Parts, to save money on postal fees, near the Co Fermanagh village of Newtownbutler. ‘I live in the south but the business is in the North,’ said McQaid. "I wholesale into the Republic of Ireland so if there’s duty, I’ll have to set up a company 200 yards up the road to sell to my customers. I’ll have to bring the same product in through Dublin instead of Belfast’ Reuters Brexit threatens life on the Irish border: in pictures A disused Great Northern Railway line and station that was for customs and excise on the border town of Glenfarne, Co Leitrim Reuters Brexit threatens life on the Irish border: in pictures Alice Mullen, from Monaghan in the Republic of Ireland, does her shopping at a former customs post on the border in Middletown, Co Armagh. ‘I’d be very worried if it was a hard border, I remember when people were divided. I would be very afraid of the threat to the peace process, it was a dreadful time to live through. Even to go to mass on a Sunday, you’d have to go through checkpoints. It is terribly stressful,’ said Mullen. ‘All those barricades and boundaries were pulled down. I see it as a huge big exercise of trust and I do believe everyone breathed a sigh of relief’ Reuters Brexit threatens life on the Irish border: in pictures A bus stop and red post box stand in the border town of Jonesborough, Co Armagh Reuters

“It is telling that now she has gone to Brussels to take over from the prime minister as we get to the crunch. Theresa May and her government are in the pocket of the DUP.”