THE turmoil in the Conservative party over the Prime Minister’s plan for a softer Brexit continued yesterday when angry Eurosceptics submitted four amendments to the government’s trade bill, arguing Theresa May has broken their trust.

Members of the hardline European Research Group (ERG), fronted by Jacob Rees-Mogg, want MPs to kill off May’s customs arrangement proposals in an amendment to Monday’s bill, calling for the UK to refuse to collect duties for the EU unless member states do likewise.

A second amendment, which is backed by the DUP and Labour’s Kate Hoey, would force the government to agree in law to a commitment to never having a border in the Irish Sea, which would kill off the EU’s backstop allowing Northern Ireland to remain in the customs union.

The four amendments to the crucial Customs Bill were put down a day before today’s publication of a white paper giving details of the Prime Minister’s plans, which infuriated Brexiteers and prompted the resignation of Cabinet ministers Boris Johnson and David Davis.

Rees-Mogg said the amendments to the Taxation (Cross-Border Trade) Bill had become necessary after May’s Chequers plan emerged. “Unfortunately, Chequers was a breakdown in trust. Brexit meant Brexit, but now it appears Brexit means remaining subject to European laws. I believe this will help the government stick to the promises it made,” he said yesterday.

Hard Brexiteers have also pledged to mount a campaign of guerrilla warfare against May’s government in an attempt to disrupt the soft Brexit proposal unveiled at Chequers, in which she proposed that the UK would share a “common rule book” of standards on food and goods after Brexit.

The amendments amount to a show of strength by hardline Brexiters, though it is not clear if they will command any wider support. In February, 62 Tory MPs – including three Scots Tory MPs Alister Jack, Stephen Kerr and Colin Clark – from the ERG signed a letter demanding that the UK achieves full regulatory autonomy after Brexit. Ross Thomson, MP for Aberdeen South, later added his name.

It also emerged yesterday May has been given a week to drop her Chequers Brexit plan or face a vote of no confidence in her leadership with Tory Eurosceptic MPs claiming to have gathered the 48 letters required to trigger a contest. They said they would submit them to the 1922 Committee of Tory backbenchers unless she changes course. May previously indicated she will stay on unless 159 Tory MPs – more than half of those in Parliament – vote against her.

The other ERG amendments would require the government to draw up primary legislation if the UK wants to remain in the EU customs union and would require the UK to have an independent regime for VAT.

Arriving at the Nato summit in Brussels yesterday, May was asked if she was expecting more resignations by Brexit-backing Tories opposed to her plan. The PM responded: “The Chequers deal is a plan that has been put together, it’s been agreed by government, we will be publishing our white paper this week which will set out more detail on it. It’s there because it delivers on the vote that people gave on Brexit, it delivers the fact that we will have an end to free movement, we will have an end to the jurisdiction of the European Court of Justice in the UK, we won’t be sending vast contributions to the EU every year, we’ll be out of the Common Agricultural Policy, out of the Common Fisheries Policy.

“We deliver that Brexit and we do it in a way that protects jobs and livelihoods and meets our commitment to Northern Ireland.”

Meanwhile, in the Commons yesterday, Shadow Foreign Secretary Emily Thornberry, deputising at Prime Minister’s Questions, took aim at the Government drawing comparisons with Gareth Southgate’s English football team. Her remarks came after Cabinet Office Minister David Lidington coupled his congratulations for the Three Lions ahead of their semi-final clash with Croatia with a tongue-in-cheek offer to buy Thornberry an England flag. Thornberry quit the Labour frontbench in 2014 after she sent a “snobby” tweet depicting a terraced house flying the St George’s flag. The pair led the main exchanges at PMQs due to May’s attendance at the Nato summit. After Lidington poked fun at Thornberry about the flag, she replied: “I may know very little about football but even I can see that England’s progress so far in the World Cup shows what can be achieved when all the individual players work effectively as a team, when there’s a clear game plan and when they’re all working together, and of course when everyone respects and listens to the manager.”