[Jo Cox MP was murdered in June]

Half of the female shadow cabinet ministers who resigned over Jeremy Corbyn’s leadership have faced death threats or warnings of violent attack, the Telegraph has learned.

Six of the dozen senior women who stepped down in the last month have faced threats of physical attack or violence, while many of the others have received intimidating messages online.

The danger from some threats has been deemed so realistic that police have been called in, while others have installed extra security measures amid growing concerns about their safety from relatives.

One former front-bencher was told she would “get it like Jo Cox did”, another was told to kill herself and a third was warned a queue of people would be outside her home “waiting to rape” her.

The threats have been so concerning that Rosie Winterton, Labour’s Chief Whip, has raised it at a shadow cabinet meeting.

The party’s ruling body has also suspended all normal constituency party meetings until September amid fears of hostility growing during the leadership contest this summer.

There are now calls from moderates to supporters of Jeremy Corbyn - who has also had death threats – to lower the tone of their rhetoric. The Labour leader’s office insists he has consistently spoken out against all forms of abuse.

This newspaper has established that half of the dozen Labour MPs who resigned from Mr Corbyn’s shadow cabinet in the days after the EU referendum have received messages warning of violence.

They range from actual acts of violence – Angela Eagle’s constituency office had a brick thrown through its window – to veiled threats in online messages: one MP was told “I hope you choke”.

Luciana Berger, the former shadow health minister, received an email saying “you are going to get it like Jo Cox did” with a photograph of a knife. She has contacted the police.

Lucy Powell received a message telling her to kill herself after announcing she would leave the frontbench over frustrations with the leadership.

One female MP and former frontbencher who asked not to be named said they had been told a “queue of refugees” would be waiting to rape them at home, while another had a specific threat of violence.

Other women MPs who stepped down said that while they had no threats of violence they received intimidating or bullying messages. Often the messages followed appearances on broadcasts criticising the leadership.

Lilian Greenwood, the former shadow Transport secretary who left last month, told The Telegraph: "The tone of the debate over the future of Labour Party has deteriorated dramatically over the course of the last year.