There's one way Theresa May can escape this customs union maze: let parliament take back control

If Theresa May is forced out by the Brexit process, we will look back on Amber Rudd’s resignation as a pivotal moment. Replacing her at the Home Office with Saijd Javid looked a neat move on Monday. Just 48 hours later, it was not so clever.

Javid, an instinctive Eurosceptic who reluctantly backed Remain in the 2016 referendum, sided with the Brexiteers in his new role as a member of the Cabinet’s Brexit sub-committee. As a result, the group blocked May’s plan for a customs partnership with the EU after Brexit. Another Remainer, the Defence Secretary Gavin Williamson, a close May ally (unlike Javid), also ignored pleas by May aides to support her, leaving her in a minority of 5-6. If Rudd had still been in her post, it would have been 6-5 in May’s favour.

The prime minister now looks lost in a maze of her own making, her authority dented again. A brief recovery after the Salisbury nerve agent attack has been stopped in its tracks by the Windrush scandal and now Brexit. She intended to win the argument for her proposed customs partnership at Wednesday’s meeting of the sub-committee and then the cabinet’s approval next Tuesday. Now her officials are scrabbling around for yet another compromise that would prevent the Brexiteer ministers Boris Johnson, Liam Fox and David Davis resigning. The trouble is that if May keeps them on board, she will face a humiliating defeat in parliament. The house of lords has already voted overwhelmingly for a customs union, and the commons will almost certainly do so when it eventually gets the chance.

There is a way out of May’s maze. She should do something that will not come naturally to her: trust parliament. Fearing a defeat on a customs union, the government has delayed two measures, the Customs and Trade Bills, originally due for debate in February. MPs also have to decide whether to overturn a lords amendment to the EU (Withdrawal) Bill calling for a customs union.

A brave prime minister would bring back the Customs or Trade Bill quickly and let MPs resolve the issue. If, as expected, a majority of MPs voted for a customs union, May could argue that the will of parliament must be respected. She might have to play charades by whipping Tory MPs against such a union. But the blocking of her plan by the Brexiteer ministers will encourage the 25 pro-European Tory backbenchers to stand firm and vote for a customs union. They would again be denounced as “traitors” and “mutineers” by the pro-Brexit press, but for once the “rebellion” would not cause May to lose sleep. In effect, it would be licensed.

Johnson, Fox and Davis would smell a rat. But could they really resign in protest at parliament being given the crucial say on an issue at the heart of Brexit? Could they flounce out because MPs had voted for a customs union? Not very democratic. Much more difficult to quit than if May tried to outmanoeuvre them by taking the customs issue to the full cabinet which, unlike the sub-committee, has a big majority of ministers who voted Remain in 2016. Similarly, putting parliament in the driving seat would make it harder for backbench Brexiteers to carry out threats to topple May by forcing a vote of confidence in her as Tory leader.

Officially, May’s option and the alternative plan to use technology to limit customs checks, favoured by the Brexiteers, are still on the table as officials draw up revised proposals. Although May allies insist that her partnership plan could be made feasible with more work, it is seen as a dead duck. But it is not a million miles from a customs union and the pro-EU Tories are not bothered about labels. So the way to bring it back to life is to work with them.

May’s instinct will be to play for extra time and search for another proposal to keep both factions in her party onside. Her powers of escapology have been underestimated in the past. But it won’t be easy this time. She should face down The Three Brexiteers by giving MPs a say, and then remind the Eurosceptics that Brexit was supposed to be about parliament “taking back control.”