Sir Keir Starmer is facing another humiliating backbench rebellion over plans to curb jury trials, as 39 MPs broke cover to urge the Prime Minister to U-turn on the plan.

Justice Secretary David Lammy announced plans to reserve jury trials only for when defendants faced serious charges such as rape and murder, and those with a likely sentence of more than three years in prison, in a bid to ease the backlog in the crown courts.

But now Karl Turner, the MP for Hull East, has written to the Prime Minister urging him to drop the plans along with 38 other Labour backbenchers.

“Many more MPs, not on this letter, have said they will rebel if necessary,” Mr Turner wrote on social media, as he shared the text of the letter.

The letter, also signed by Mother of the House of Commons Diane Abbott, branded the Government’s proposals “an ineffective way of dealing with the crippling backlog in cases in our criminal justice system”.

The MPs, whose number is largely made up of the left of the party, added there is a “growing number of our colleagues who are not prepared to support these proposals” when it comes to the Commons.

“The drastic restriction of the right to trial by jury is not a silver bullet. To limit a fundamental right for what will make a marginal difference to the backlog, if any, is madness and will cause more problems than it solves,” the letter added.

The MPs suggested a series of alternatives to tackling the backlog, including increasing the number of sitting days for courts.

They said: “Around 130,000 sitting days are available to the courts, yet, despite a capacity crisis, sitting days are restricted by 20,000 a year.”