There's a big elephant in Theresa May's Cabinet room when it comes to Brexit – and it's not the DUP

Some of May's MPs are now threatening to topple her if she doesn't give them what she foolishly promised a long time ago

May is at a fork in the road and there's no turning back (Getty)

“There’s no need to work out all the fine details now,” Theresa May tells Brexiteer Cabinet ministers and Conservative MPs when they challenge her about the €64,000 question on Brexit: the long-term UK-EU relationship.

It is the elephant in the Cabinet room. The Prime Minister knows her ministers are deeply divided, and so has prevented any real discussion of it during the 18 months since the referendum. But her strategy has been blown apart by this week’s row over the proposed deal on the Northern Ireland-Ireland border.

It was a case of “so near, so far” for May when the Democratic Unionist Party (DUP) blocked a deal she was ready to sign in Brussels on Monday, allowing the EU to open talks on a long-term trade deal at its summit next week.

The DUP is now making May sweat, deploying the same weapon as the 27 EU countries – time, namely the UK’s lack of it. The problem is that both the DUP, on whose 10 MPs May’s minority administration depends, and the Irish Government have a veto. Finding language acceptable to both sides is tricky; too many concessions to the DUP and Ireland could pull the plug.

Yet both the DUP and Dublin want a deal because the economies of their two countries need a post-Brexit trade agreement. So a deal is still possible next week.

May’s biggest problem now is her own party – the third audience she must satisfy in her increasingly complex game of multi-dimensional chess.

The DUP’s actions have lifted the lid on the simmering dispute between soft Brexiteers led by Philip Hammond, who want to stick close to EU regulations to cushion the economic impact, and hard Brexiteers led by Boris Johnson and Michael Gove, who want a clean break so the UK is freer to strike trade agreements with non-EU nations. They have swallowed the May-Hammond medicine of a two-year transitional phase virtually on current EU terms, but fear the UK would be trapped there forever and so would never really leave.

It is no coincidence that members of the hard Brexit brigade have long supported the UK becoming a low-tax, low-regulation economy – a European version of Singapore. They claim they also want a free trade deal with the EU, the ultimate “cake and eat it” strategy (but would be happy if there is no deal). The EU27’s nightmare scenario is being undercut by a more competitive neighbour with lower standards. So they will never allow the UK to enjoy the benefits of the single market and customs union without the regulatory responsibilities.

Foolishly, May announced Britain would leave the single market and customs union and European Court of Justice’s remit – a hard Brexit – before the implications were worked through. They now dawn on ministers as they grapple with issues like the Irish border.

David Davis, the Brexit Secretary, made clear the proposed “regulatory alignment” with Ireland would be UK-wide – not just for Northern Ireland (unacceptable to the DUP and many Tory MPs). But in trying to allay DUP fears, Davis provoked a backlash from Brexiteer backbenchers and their Cabinet allies. They view “regulatory alignment” as soft Brexit, not the hard version promised by May. So they are renewing their dark threats to topple her if she goes down what they see as the soft Brexit route.

Their support for May was always conditional. “We thought we had a deal,” one senior backbencher told me. “She needs us onside to keep her job. But that means delivering the Brexit she promised.”

At Prime Minister’s Questions today, May tried to reassure her Brexiteer MPs, repeatedly saying the UK will leave the single market and customs union. She expressed the hope that tricky stuff like the Irish border would be settled in phase two of the EU talks.

But now she is struggling to clear the hurdle of phase one. The genie of the “end state” relationship is out of the bottle and will be impossible to put back.

There was always going to come a time when May had to get off the fence – and either back Hammond’s version of Brexit or throw her lot in with the hardliners. I suspect the centre of gravity in the Cabinet leans more towards Hammond’s softer version. As one member put it: “It’s about protecting the economy.”

Similarly, there would be a majority in the Commons for that, rather than no deal and/or a hard Brexit. That’s why the Brexiteers are panicking – and threatening May again.

The crunch was going to come at some point during trade talks next year but it is suddenly upon May. She can no longer put off a confrontation with the Brexiteers. She should ignore any threats to resign or bring her down and face them down.

Via an unplanned detour on the Irish border, May has reached a fork in the road; there is no third way.