The former Labour MP for Lewisham East has resigned from the party after 45 years, citing its “slow, reluctant and inadequate” response to antisemitism.

Bridget Prentice, who served as MP for the London constituency from 1992 until 2010, published her resignation letter via Twitter on Tuesday, setting out her reasons for leaving the party. Top of the list was the party’s inability to act decisively on its antisemitism problem.

She described how she had “watched in horror as Jewish members have begged for support against the growth of antisemitism both within and without the party.

“Mealy mouthed words have replaced what should have been a strong and determined condemnation of the bullies and bigots.”

Ms Prentice, who served as a whip from 1995 and in a number of governmental roles during the party’s 13 years in power from 1997 to 2010, described Labour’s “slow, reluctant and inadequate” response to such antisemitism, saying that “even when complaints were upheld, the punishment was often no more than a slap on the wrist.

“For a pregnant woman MP to be bullied out of the party is shameful and embarrassing”, Ms Prentice continued, referring to Luciana Berger, the MP for Liverpool Wavertree, who resigned from the party in February citing its “institutional antisemitism”.

Ms Prentice also challenged Jeremy Corbyn’s behaviour as Labour leader, writing that “by not standing up to the bullies and antisemites…Jeremy showed no leadership.

“Leaders stand up to be counted. They root out the evil; they show that such racism will not be tolerated. They don’t twist and turn to find ways of keeping their supporters on board when those self-same supporters have been shown to be racist, antisemitic and bullies.”

Her announcement came as Sheila Murphy, Labour’s former North West regional director and a senior campaign staffer for Ed Miliband, Yvette Cooper and Luciana Berger, also said she was quitting the party, saying she felt like she had been “in an abusive relationship.”

Ms Murphy, who was a Labour member for 49 years and had campaigned for every party leader since Harold Wilson, described how among other things “with antisemitism, they try and tell you it’s not happened in the party – but it certainly is.”

They join a growing list of former Labour female politicians to have resigned their membership, including Dame Pauline Green, who once served as leader of the European Parliamentary Labour Party, and Jane Kennedy, who served as Labour MP for Liverpool Wavertree before Ms Berger.

A number of current Labour MPs retweeted Ms Prentice’s letter, including Wes Streeting and Jess Phillips.

Janet Daby, the current MP for Lewisham East, described how “deeply saddened” she was to see the former MP for her constituency leave the party.

“You rightly raise serious concerns in your letter & I will make sure they are heard at every level of the party”, she tweeted.