Theresa May. Picture: REUTERS
Theresa May. Picture: REUTERS

British Prime Minister Theresa May faces a fight on two fronts this week, battling to convince her own ministers and then Brussels as the Brexit talks come to a head.

May must see off the threat of a cabinet mutiny and then try to overcome a logjam in divorce negotiations at a summit in Brussels, with a breakthrough still seeming elusive.

Time is running out on Britain’s EU exit talks — and this week’s gathering of EU leaders could prove decisive on the path to striking a deal between London and Brussels.

With Britain set to leave the bloc at the end of March, European Commission head Jean-Claude Juncker is demanding "substantial progress" this week, specifically on the vexed issue of the UK’s border with the Republic of Ireland.

Giving the talks a head-start, Britain’s Brexit secretary Dominic Raab was in Brussels on Sunday for an unannounced meeting with EU chief Brexit negotiator Michel Barnier. "With several big issues still to resolve, including the Northern Ireland backstop, it was jointly agreed that face-to-face talks were necessary ahead of this week’s October European Council," said a spokeswoman for Raab’s ministry. As for May, she not only has to win over her continental counterparts but also increasingly restive allies back home.

The hard work starts for May on Tuesday when she will rake over the Irish border issue with her cabinet, amid speculation that further ministers could quit if the PM ploughs on with her proposals. David Davis, who quit as Brexit secretary in July over May’s broad blueprint, wrote in The Sunday Times newspaper that her plans were "completely unacceptable" and urged ministers to "exert their collective authority" this week.

Neither London, Dublin nor Brussels wants to see checks imposed on the border between the UK’s Northern Ireland and the Irish Republic — but the problem persists of finding a way to square that aim with May’s desire to leave the European single market and the customs union.

Britain has proposed that it continue to follow EU customs rules after Brexit as an option to keep the border open until a wider trade deal is agreed.

May says this will be temporary, but her spokeswoman was forced to clarify the point after media reports that the final "backstop" arrangement will have no legal ending date.

The EU’s suggestion would see Northern Ireland remain aligned with Brussels’ rules, thus varying from the rest of the UK.

The plans have infuriated the pro-Brexit hard core of May’s centre-right Conservative Party — not to mention her Northern Irish allies in the Democratic Unionist Party (DUP).

For a thin majority in parliament, the minority Conservative government relies on the DUP, Northern Ireland’s biggest party.

The DUP are staunchly pro-UK, pro-Brexit and opposed to any moves that could put distance between Northern Ireland and the British mainland.

The DUP have threatened to vote down the budget if May gives way to Brussels.

Writing on Saturday in the Belfast Telegraph newspaper, DUP leader Arlene Foster said the backstop would be "the permanent annexation of Northern Ireland". After talks with senior figures in Brussels last week, Foster reportedly said a no-deal Brexit was now most likely, according to an e-mail between senior British officials leaked to The Observer newspaper.

Leading Conservative eurosceptic Jacob Rees-Mogg said on Saturday there were 39 like-minded Conservative MPs who "will not turn" from opposing the current plans.