At an angry meeting, Labour MPs have accused the party’s most senior official of covering up the number of complaints alleging antisemitic threats and comments from party members.

Margaret Hodge, Ruth Smeeth and Catherine McKinnell criticised the party’s leadership following claims that the general secretary, Jennie Formby, has been slow to tackle dozens of claims of abuse and threats from Labour party members.

It followed a motion, unanimously passed by the meeting of the parliamentary Labour party in Westminster, which called on the leadership to do more to tackle antisemitism in the party.

The motion called on the leadership “to adequately tackle cases of antisemitism, as failure to do so seriously risks antisemitism in the party appearing normalised and the party seeming to be institutionally antisemitic”.

A Labour source denied that the party was covering up the number of allegations, and said that both Jeremy Corbyn and Formby have made tackling claims of antisemitism within the party a priority.

Corbyn apologised 10 months ago for the “hurt and pain” caused by instances of antisemitism within Labour and pledged to redouble his “efforts to bring this anxiety to an end”.

MPs were particularly angry at Formby’s refusal to release data showing the number of outstanding cases still to be heard by the party.

Outside the meeting, Hodge, the MP for Barking, said: “The resolution was unanimously supported by the parliamentary Labour party, and then the general secretary of the Labour party basically said she wasn’t prepared to give us the information that was required in the resolution.

“For me if you want to get rid of the cancer of antisemitism in the Labour party you have to have complete transparency. She has refused to do that. Jennie’s message was vague.”

The motion posed 11 questions that it wants the party leadership to answer, including how many cases of antisemitism-related disciplinary cases remain outstanding, when a promised antisemitism code of practice will be completed and how the party is engaging with targets of antisemitic abuse.

Last month Jim Sheridan, a former Scottish Labour MP, had his suspension lifted after an investigation into a Facebook post in which he wrote: “For all my adult life I have had the utmost respect and empathy for the Jewish community and their historic suffering. No longer due to what they and their Blairite plotters are doing to my party and the long-suffering people of Britain who need a radical Labour government.”

Sheridan has since apologised to the Jewish community, and said: “My accusers were misguided and overreacted to what was intended to highlight my personal frustration and criticism of those intent on undermining our leadership.”

Corbyn has repeatedly said he “will not tolerate antisemitism in any form”, but he had to clarify comments made in 2013 in which he accused a group of British Zionists of having no sense of irony. He has said he was using the term Zionist in its “politically accurate sense”.

A statement released by Formby before the meeting said the party had made some progress in tackling antisemitism and had radically changed the party’s complaints procedures.

“I had witnessed first-hand that our complaints and disputes procedures were not fit for purpose, with longstanding cases that hadn’t been dealt with, alongside new cases coming in, especially in relation to appalling antisemitic tropes and conspiracy theories, mostly on social media,” she said.

A Labour source said Formby could not override previous decisions by the party’s NEC regarding data.

