May’s grip on Brexit and on power is so fragile that I now suspect a general election could happen

For the prime minister, a Final Say referendum would feel like an admission that she had failed to implement the voters’ 2016 decision, whereas an election could be used to try to pin the blame for that on MPs

When the Cabinet met this morning, ministers expected Theresa May to hold the third Commons vote on her Brexit deal tomorrow. But when she updated MPs this afternoon, May admitted there is not yet enough support for her unloved withdrawal agreement.

The clincher, it seems, was a telephone discussion at lunchtime with Arlene Foster, the DUP leader, who did not drop the party’s opposition to the agreement – itself a necessary first step to persuading Tory Eurosceptics to switch sides.

Of course, it is not exactly in this prime minister’s nature to change course.

She still intends to stage another vote, perhaps on Thursday, and certainly before 12 April, when the UK is scheduled to leave the EU if the Commons has not approved a deal or the government has not asked the EU for another extension to the Article 50 process.

May surprised MPs by appearing to play down the prospect of a no-deal exit, which some ministers think is her second preference after her agreement.

“Unless this House agrees to it, no deal will not happen,” she said. She warned that “slow Brexit,” with a long extension (and possibly in the end a soft Brexit), or no Brexit, would not be acceptable.

All roads, conveniently, lead back to her deal.

Answering MPs’ questions, she denied she was taking no-deal off the table (as did Downing Street), but it sounded like it unless this is yet another confusing flip-flop. May knows the Commons has voted against the no-deal option twice and will probably do so again this week.

However, the prime minister was less conciliatory when it came to other Brexit options.

Pointedly, she refused to commit to implementing any consensus that may emerge from upcoming “indicative votes” on a Plan B. MPs are expected to approve the votes tonight, and to hold them on Wednesday. The options include: a customs union; a customs union and Single Market membership; a Canada-style free trade agreement; revoking Article 50; a Final Say referendum; May's deal; and no-deal.

Ministers had drawn up plans to take control of the indicative votes process but the Cabinet decided today not to press ahead, instead leaving a cross-party group of senior MPs in the driving seat. Although May promised to “engage constructively,” many MPs rightly don’t trust her to do that. By not owning the process, it will be easier for ministers to reject a Commons consensus for a customs union or a Common Market 2.0 plan (the Single Market and a customs union).

May was “sceptical” about indicative votes, saying they could produce contradictory outcomes or none at all, or something unacceptable to the EU. So if they happen, the votes will be a big test for MPs; they have only one shot at getting this right. They need to show a genuine willingness to compromise rather than vote down everything other than their first choice.

I suspect May will argue that the indicative votes are not binding, and that parliament’s recommendation of a soft Brexit would be at odds with the Tories' 2017 election manifesto.

This latter argument is open to question: many Tory pledges have been ditched – on social care; a new generation of grammar schools; a Commons vote on hunting and limiting rises in the state pension and winter fuel payments. Manifestos are changed when governing parties lack a majority – as we saw during the 2010-15 Con-Lib coalition years, and under the Tories’ confidence and supply agreement with the DUP. So why must May’s Brexit pledges be set in stone?

Ultimately, ministers are gearing up for a constitutional clash with parliament. If MPs tried to legislate for a soft Brexit – admittedly an unprecedented move – it would leave the government impotent.

Ministers are warning that the only way to resolve such a stand-off would be a general election. Although this would be partly aimed at pressurising Tory MPs – who do not want May to lead them into another election – to vote for her agreement, for the first time I suspect the prospect of an election is a real one.

May allies suggest she would prefer an election to a referendum – even the proposal by Labour backbenchers Peter Kyle and Phil Wilson to make approval of her deal conditional on a referendum. She told MPs this would be a re-run of 2016 because Kyle and Wilson want Remain on the ballot paper.

For May, a Final Say referendum would feel like an admission that she had failed to implement the voters’ 2016 decision. An election could be used to try to pin the blame for that on MPs. Although May admitted today she needed to “take care” with her language after her counter-productive, Trump-like attack on MPs last week, she has not said sorry and such a blame game is still part of her survival plan.

While cabinet manoeuvres against May are on hold after the weekend’s botched coup, her grip on power is fragile. The plotting will doubtless return. Indeed, May’s dismissal of the indicative votes process in advance of it even starting confirms that she is not the right person to build the consensus the country desperately needs.