A warning that Theresa May will get a knife “stuck in her front” has triggered an angry backlash.

The prime minister faces a difficult week described as the “killing zone” amid deep divisions within the Conservative Party over her Brexit strategy.

Some of May’s critics have claimed the 48 letters needed to trigger a no confidence vote in her leadership could soon be reached.

If 158 Tory MP then voted against her she would be ousted as leader.

A former Tory minister told The Sunday Times: “The moment is coming when the knife gets heated, stuck in her front and twisted. She’ll be dead soon.”

“Assassination is in the air,” one Tory MP told the paper.

Another source described as an ally of former Brexit Secretary David Davis said May was now entering “the killing zone”.

The language was condemned by Tory MPs on both the pro-Brexit and pro-Remain sides of the party.

Former Cabinet minister Theresa Villiers, a Brexiteer, said the comments about the PM in the newspapers were “disturbing”.

May is due to face her MPs at a meeting of the backbench 1922 committee on Wednesday.

One Conservative MP told the Mail on Sunday the prime minister should “bring her own noose” to the “show trial” – such was the anger at her leadership.

Backbencher Johnny Mercer last week described May’s government as a “shitshow”.

But he hit out at how some of his colleagues had chosen to make their criticisms.

“I would never use the language of some MP’s against the PM today, and condemn it utterly,” he tweeted.

Brexit minister Suella Braverman today refused three times to say whether she would support May if a no confidence vote was triggered.

Asked by Sky News if she would condemn the “brutal” language used about the prime minister, Braverman declined.

“Colleagues are free to express themselves in the way they wish,” she said.

 Scottish First Minster Nicola Sturgeon also told Tory MPs to “get a grip”.