Prime Minister Theresa May will tell Parliament on Monday that 95 per cent of Britain’s divorce deal has now been settled but will repeat her opposition to the European Union's proposal for the land border with Northern Ireland.

Facing some of the fiercest criticism to date over her Brexit plans after the two sides failed again to reach agreement at a summit last week, May will try to calm passions in Parliament where her strategy has angered eurosceptics and EU supporters alike.

‘Clear’ deal

With just over five months until Britain leaves the EU, talks have stalled over a disagreement on the so-called ‘Northern Irish backstop’, an insurance policy to ensure there will be no return to a hard border on the island of Ireland if a future trading relationship is not agreed in time.

But May's attempt to unlock the talks by considering an extension to a status-quo transition period beyond the current proposed end date of December 2021 has further stirred passions at home.

In an attempt to highlight how much progress has been made in more than a year of talks with the EU, May will tell Parliament the government has reached agreement on everything from Gibraltar to future security over the last three weeks. “Taking all of this together, 95 per cent of the Withdrawal Agreement and its protocols are now settled,” she will say, according to excerpts from her statement to Parliament. “The shape of the deal across the vast majority of the Withdrawal Agreement is now clear.”

But the withdrawal agreement, or the terms of Britain's divorce, cannot be signed off until the two sides agree on the Northern Irish backstop.

Rejecting EU’s proposal

At an EU summit last week, any such agreement seemed just as far off as it did months earlier, with EU officials and diplomats saying May had offered nothing new to unlock the talks. Since then, May's proposal to extend the transition period has done little to calm anger among eurosceptics in the governing Conservative Party, who fear she is leading Britain into a deal that will make Britain a “vassal state”, unable ever to leave the EU.

On Sunday, Brexit minister Dominic Raab pushed the suggestion forward, saying London could accept such a move if the EU dropped its proposal for the backstop, which May says would tear Northern Ireland from mainland Britain.

May will repeat her opposition to the EU proposal—for Northern Ireland to remain in the bloc's customs union, potentially creating barriers to trade with the rest of Britain—as she tries to ease growing frustration among her parliamentary partners, a Northern Irish party.

“As I set out last week, the original backstop proposal from the EU was one we could not accept, as it would mean creating a customs border down the Irish Sea and breaking up the integrity of the UK,” she will say. “I do not believe that any UK Prime Minister could ever accept this. And I certainly will not.”