THERESA May has been given a week to drop her Chequers Brexit plan or face a vote of no confidence in her leadership, it has been reported.

Angry Tory Eurosceptic MPs claim to have amassed the 48 letters required to trigger a contest and will submit them to the 1922 Committee of Tory backbenchers unless she changes course, sources have told a London newspaper.

It is also being reported this morning that the Prime Minister is facing a "relentless guerrilla war" from hardliners in a bid to make her abandon her blueprint for a softer Brexit.

The developments come amid turmoil in the Conservative party after May agreed the plan last Friday with her Cabinet - which includes sticking with EU goods rules and collecting customs tariffs on behalf of the bloc Ex Brexit Secretary David Davis and Foreign Secretary Boris Johnson stormed out of their jobs in protest, along with former junior minister Steve Baker and two Tory vice chairs Ben Bradley and Maria Caulfield.

An anti-EU Tory told the Telegraph: "If the policy doesn't change the letters will go in.

"Her deal will be rejected by Brussels, Downing Street must know that. They are either being incompetent of disingenuous."

Another told the Daily Mail: “This is not going to stop. We want the Chequers plan killed, and we want it killed now. This is guerrilla war.”

Tory MP Andrew Bridgen was the first to hand his letter to chair of the 1922 Sir Graham Brady yesterday. In it he said the Prime Minister had “insulted” the intelligence of voters with her promises.

Meanwhile, warnings surfaced that the Chequers plan may fail to gain the support of enough MPs to pass the Commons.

One Cabinet minister told the Times: “I think that the Chequers compromise is going to be voted down in the Commons.

“I can’t see how Labour don’t reject it outright. I think there’s quite a good chance nobody gets what they want and it’s not clear where that leaves us.”

Another said: “We need to convince the Brexiteers that we’ve left, and that we will diverge but this will take 15 years not one. We can’t do it in one leap, but we will get what they want.”

Elsewhere, it is being reported that ministers are drawing up secret plans to stockpile food and medicines in case the UK crashes out of the EU without a deal in March 2019.

The scheme is said to be one of 300 contingency measures for the worst case scenario being spearheaded by new Brexit Secretary Dominic Raab.

A spokesman for the Prime Minister said yesterday: "We've always said it is sensible to make preparations for all scenarios and that includes no deal."

May is to set out the full details of her plan for what type of future relationship she wants with the EU in a White Paper tomorrow.

But while pressure mounted at home over May's plans, EU figures have given them some positive reaction.

Michel Barnier, the EU chief Brexit negotiator, said he was looking forward to a "constructive discussion" on the White Paper, noting that "after 12 months of negotiations we have agreed 80% of the negotiations."

In Dublin, Irish Taoiseach Leo Varadkar, was also upbeat telling the Dail: "If the United Kingdom was able to relax some of its red lines, then the European Union could be flexible too. We are now entering into that space."

The German Chancellor Angela Merkel also appeared sympathetic.

"We are looking forward to interesting discussions but we will also have these inspired by the spirit of friendship and the wish to have good relations in the future."