Last-ditch negotiations in the Brexit process have descended into open hostility as one senior minister accused the EU of playing “games” with just three days to go until MPs vote on Theresa May‘s plans.

After an extraordinary exchange between the Brexit secretary Stephen Barclay, and the EU’s chief negotiator on social media, the Commons leader Andrea Leadsom said she was was “deeply disappointed with what we’re hearing coming out of the EU”.

“I do have to ask myself what games they are playing here,” the cabinet minister told Reuters after Mr Barclay accused Michel Barnier of trying to “rerun old arguments” as hopes of a Brexit breakthrough began to fade before Tuesday.

It comes as Westminster prepares for another week of political turmoil, with MPs gearing up to vote on the prime minister’s deal for a second time.

Britain Before Brexit: Northern Ireland Show all 12 1 /12 Britain Before Brexit: Northern Ireland Britain Before Brexit: Northern Ireland Derry, Londonderry A garage door displaying unionism, bolted shut, like a visual representation of Brexit Britain, locked to outsiders, safeguarding what’s inside Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Derry, Londonderry Rossville Street, the site of Bloody Sunday, where messages demand a severance with England. From this perspective, Britain is England in sheep’s clothing, the real empire, the centre of colonial power Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Bangor A political message in paint not yet dry, still forming, setting, adjusting, or in old paint finally eroding, melting away Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Bangor Moral judgement frames a residential view. The message seeks to make everybody involved in the religious narrative: those who don’t believe are those most in debt Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Castlerock The beach is sparse and almost empty, but covered in footprints. The shower is designed to wash off sand, and a mysterious border cuts a divide through the same sand Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Belfast Two attempts to affect and care for the body. One stimulated by vanity and social norms and narratives of beauty, the other by a need to keep warm in the winter night Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Belfast The gate to an unclaimed piece of land, where nothing is being built, where no project is in the making, where a sign demands the creation of something new Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Derry, Londonderry Under a motorway bridge a woman’s face stares, auburn and red-lipped, her skin tattooed with support for the IRA and a message of hostility to advocates of the Social Investment Fund Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Derry, Londonderry The Fountain Murals, where the curbs and the lampposts are painted the red, white, and blue of the Union Flag. A boy walks past in the same colours, fitting the scene, camouflaged Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Coleraine A public slandering by the football fields, for all to see or ignore. I wonder if it’s for the police or for the community Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Belfast A tattoo parlour, where the artist has downed tools, momentarily, bringing poise to the scene, which looks like a place of mourning, not a site of creation Richard Morgan/The Independent Britain Before Brexit: Northern Ireland Derry, Londonderry A barrier of grey protects the contents of this shop, guarding it from the streets outside, but it cannot conceal it completely, and the colours of lust and desire and temptation cut through Richard Morgan/The Independent

Unless Ms May manages to secure last-minute concessions from Brussels over the weekend and into Monday, it appears she will suffer yet another heavy defeat in the House of Commons, throwing the Brexit process into further uncertainty.

Ms Leadsom said she was still hopeful of a breakthrough, but added it would depend on the EU “coming to the table and taking seriously the [UK’s proposals]”.

During a speech on Friday, Ms May pleaded with EU leaders to give ground in the negotiations as she told them: “Let’s get it done”.

But hours later Mr Barnier indicated on his Twitter account that if the UK did not like the deal on the table, it could accept an alternative already rejected outright by the prime minister in the negotiating process.

In response, the Brexit secretary Mr Barclay said: “With a very real deadline looming, now is not the time to rerun old arguments. The UK has put forward clear new proposals. We now need to agree a balanced solution that can work for both sides.”

Ms May had been seeking legally binding assurances that the UK could not be tied indefinitely to the EU through the backstop in an attempt to win round MPs. But in a sign ministers are preparing to go back to the Commons on Tuesday without fresh concessions, chancellor Philip Hammond said such fears about the backstop were overblown.

In an interview with the Financial Times, he urged Tory MPs to back the agreement anyway, saying it would enable him to start spending the “insurance fund” built up in case of a no-deal break.