MPs and Labour grandees clamouring for Jeremy Corbyn to remove the whip from Chris Williamson are “bullies” who need to be stood up to, one of Britain’s most prominent trade unionists said today.

Deputy leader Tom Watson led a pile-on of MPs who rejected a disciplinary panel’s ruling on Wednesday that Mr Williamson should have the whip restored after being suspended for saying Labour had been too apologetic over its record of fighting anti-semitism.

Party general secretary Jennie Formby said this evening that the whip had not actually been restored after Keith Vaz, who sat on the panel which decided to restore it, declared the decision needed to be revisited. It is to be revisited by the national executive on July 9.

Aside from MPs, Momentum founder Jon Lansman had joined Mr Watson’s demand that Mr Corbyn act unilaterally to overrule the panel’s decision and resuspend the MP for Derby North, whose “democracy roadshow” promoting reforms that would make Labour MPs and councillors more accountable provoked bitter resentment on the right of the parliamentary party. Shadow Brexit secretary Keir Starmer also joined the chorus of condemnation.

Activists Owen Jones and Ash Sarkar, also associated with the left of the party, attacked the decision to let Mr Williamson return as well.

But former Aslef president and current Doncaster councillor Tosh McDonald told the Morning Star that “only a few months ago those same MPs signed a letter saying he should be suspended and face this disciplinary procedure.

“Now they want to reopen that because they don’t like the result. Well they can’t demand that unless they also want to reopen the cases of Marc Wadsworth and Jackie Walker.

“As a friend and comrade of Chris’s I know there isn’t a racist bone in his body. He’s one of the best campaigning socialist MPs we’ve ever had. The ones trying to silence him are those who don’t want campaigning MPs, don’t want an end to austerity.

“What these MPs’ letter is doing is nothing short of bullying. As a trade unionist I’ve fought bullies all my career and you have to stand up to them.”

He called on Mr Williamson’s supporters to find their voices in defending him: “There’s that saying that all it takes for evil to prosper is for good people to do nothing. Well, there’s many good comrades who are doing nothing at the minute.”

Campaign group Jewish Voice for Labour said yesterday it welcomed the lifting of Mr Williamson’s suspension, and criticised media focus on the MP’s opponents.

“There is huge support for Chris within and outside the party and this had not been reflected in the media coverage,” it said.

NEC members hostile to Mr Williamson have briefed the Huffington Post that they believe they have the numbers to overturn the panel’s ruling and have the decision referred to the national constitutional committee. The July 9 executive is also rumoured to be the scene of a planned showdown on Brexit, with pro-Remain members determined to force Mr Corbyn to renege on the party’s promise to respect the result of the 2016 referendum.