Joan Ryan, the chair of the Labour Friends of Israel group, is facing a motion of no confidence at her local constituency party later this week after left-wing activists accused her of “smearing Jeremy Corbyn”.
Ms Ryan, the MP for Enfield North is accused of contributing to a “trial by media” of the party leader and a group of activists is now calling for an open selection process to choose another candidate to be their parliamentary representative.
The motion submitted to Ms Ryan’s local party says: “Our MP has smeared his character without him having the right to a fair and balanced defence.”
Accusing her of acting like “an independent MP in all but name”, the activists behind it say she “has fuelled and indeed inflamed trial by media” of the Labour boss.
In response, she said: "I joined this party 34 years ago to fight racism. Antisemitism is racism.
"Nothing will stop me standing up and speaking out. It is my duty to do so. This bullying, this vindictive behaviour will never stop me doing what is right."
Ms Ryan, who was first elected in 1997, has been a vocal critic of Mr Corbyn in recent weeks.
Writing for the JC last week, Ms Ryan said she was “appalled” at Mr Corbyn’s failure to tackle antisemitism and his association with hardline Palestinian groups.
Ms Ryan, who is not Jewish herself, has been an outspoken supporter of Israel for many years.
It comes as the veteran MP Frank Field revealed he has been bombarded with death threats over his decision to quit Labour and sit as an independent in protest at Mr Corbyn’s handling of antisemitism within Labour.