Yvette Cooper has called on Jeremy Corbyn to do more to curb the online abuse of Labour MPs after revealing that she has received death threats.
Ms Cooper said one Twitter user claimed they wanted to "behead" her and said Mr Corbyn, who was re-elected leader of the party on Saturday, and shadow chancellor John McDonnell should "back party staff when they try to tackle abuse".
Writing in the Sunday Telegraph, the former shadow foreign secretary said: "Jeremy Corbyn has rightly condemned abuse many times. But when you are the leader of a party with a problem, especially when you have just been re-elected, you should use your authority to deliver action not just words."
She told the paper: "The worst I get as a Labour MP is usually from the far right. Recent grim tweets include an Australian who wants to behead me and a Trump supporter who hates refugees.
"But no matter where it is from, abuse and intimidation entrench prejudice, silence debate and poison democracy. Even a small minority can drag everyone else down."
She said Mr Corbyn and Mr McDonnell should "insist on higher standards and proper enforcement".
"Don't leave it to me to put proposals to the NEC after a year of calling for action - take a lead. I want them and all MPs to challenge supporters as well as opponents who try to use vitriol to silence others," she said.
Ms Cooper also urged the party to stamp out other forms of abuse, including party members calling each other names such as "scum", "dyke", "zio", and "paki" and the heckling of journalists.
"Frankly I don't care where in the party this kind of abuse comes from, it has to stop," she said.
"We cannot allow a minority within our party to create a climate of hostility. Good people must not be driven away or silenced. We should defend our values together."
