Pro-remain Tories were threatening a fresh Commons rebellion as Theresa May ended a marathon meeting of her Brexit war cabinet on Thursday night.
The eight-hour meeting at Chequers was called to agree solid positions on EU withdrawal ahead of a fresh round of talks with the bloc, but it was unclear if there was a major breakthrough.
Squabbling ministers could be the least of the Prime Minister’s woes, however, as it was discovered Conservative backbenchers were plotting to challenge May in Parliament over keeping a customs union with the EU.
Remainer rebel Anna Soubry revealed on Twitter she had cross-party support for a new amendment to the Government’s trade bill which would mandate the UK to form a customs union with Brussels after Brexit.
May will be forced to take the threat seriously as Labour looked set to switch position.
Just hours before Soubry went public, Shadow Foreign Secretary Emily Thornberry said her party supported a customs union that would look “pretty much like” the current one after withdrawal.
Soubry said she had widespread support for her move, tweeting: “It would be in the national interest if the Government & official Opposition also backed it.”
The Chequers “away day” saw the inner Cabinet committee discuss the impact of Brexit on the automotive sector, agri-foods, digital trade, as well as the overall future economic partnership the UK is seeking to reach with the EU.
May will set out the Brexit agenda in a major speech next week following a meeting of the full Cabinet.
Labour leader Jeremy Corbyn is also to unveil a competing vision of how Brexit should work in what is being billed as a significant address on Monday, after some backbenchers called for more clarity from the leadership.
Thornberry said Labour favoured the UK jointly negotiating new trade deals with the EU, telling LBC: “Technically, because we are leaving the European Union we can’t be in the customs union that we are in now.
“So, we leave and then we have to negotiate a new agreement. That we think is likely to be a customs union that will look pretty much like the current customs union.”
The trade bill is not expected to be debated by MPs until after Easter.
According to reports, the Chequers meet saw ministers agree on the phrase “managed divergence” to describe the nature of EU withdrawal and that the UK’s opening position would be to seek mutual recognition on goods standards.
It is thought the UK will suggest a dispute settlement mechanism, which is not the European Court of Justice, which will manage the process of divergence.
After the meet at the country retreat, however, Twitter was awash with briefing and counter-briefing from government sources with Brexiteer and Remainer sources both claiming victory.
The lengthy Chequers meeting included dinner which consisted of a starter of cream of sweetcorn soup, ham hock croquette and cured duck and egg yolk, followed by a main course of slow braised Guinness short rib of Dexter beef with onions, parsnip mash and root vegetables, with a dessert of lemon tart with raspberry sorbet and fresh raspberries.
Labour’s Shadow Brexit Secretary Keir Starmer, meanwhile, chimed in when the BBC’s Nick Robinson pondered what happened in the room.