Over one hundred MPs and peers have signed an open letter to Jeremy Corbyn demanding that he intervene and review a decision to readmit Chris Williamson to the Labour Party this week despite his record of supporting antisemites.

The letter called on Mr Corbyn to "show leadership” by asking for “this inappropriate, offensive and reputationally damaging decision to be overturned and reviewed.”

Derby North MP Mr Williamson was allowed back into the party four months after he was suspended after suggesting Labour had been "too apologetic" over antisemitism.

A three-person panel decided on Wednesday to reject a recommendation by party officials to refer the MP to the next stage of Labour's disciplinary process.

MPs including deputy leader Tom Watson, who is the only member of the shadow cabinet to have signed the statement saying “ultimately, it is for Jeremy Corbyn to decide whether Chris Williamson retains the Labour whip.

“He must remove it immediately if we are to stand any hope of persuading anyone that the Labour Party is taking antisemitism seriously.”

Statement on Chris Williamson pic.twitter.com/WGYx9os2A0

— Tom Watson (@tom_watson) June 27, 2019

It is understood that Keith Vaz, the Labour MP for Leicester East, led calls for Mr Williamson’s suspension to be dropped despite allegations of a "pattern of behaviour" going back months on issues involving antisemitism.

Mr Vaz sat on the NEC disputes panel which found he broke Labour rules - but issued him with a "formal warning" and restored his membership.

MPs responding to the decision said: “We cannot overstate the depth and breadth of hurt and anger felt about the readmission of Chris Williamson into the Labour Party and the questions that arise about the fairness of the process.

“The officer recommendation - that Chris Williamson should be referred to the National Constitutional Committee for action - was ignored by the members of the NEC panel.”

Mr Williamson was branded a "Jew baiter" in December after signing a petition defending notorious antisemite Gilad Atzmon.

Anti-racist advocacy group Hope Not Hate has said Mr Atzmon was “an antisemite who has promoted the works of Holocaust deniers”, while the Community Security Trust described Mr Atzmon book, the Wandering Who?, as “quite probably the most antisemitic book published in this country in recent years”.

MPs who signed the statement also raised concern that the panel which made the decision to readmit Mr Williamson was “changed at short notice”, and described the practice as “highly irregular.

“Justice needs to be seen to be done and this process has not done that.

“Given that the Labour Party is being investigated by the EHRC over allegations of institutional antisemitism this case is particularly important.

“It is clear to us that the Labour Party’s disciplinary process remains mired by the appearance of political interference. This must stop. We need a truly independent process.”

Thank you to the members of the Parliamentary Labour Party who won’t accept Williamson back into the fold so easily as the Party’s leadership.

There is still time to add your name. pic.twitter.com/8Ql55VbztK

— Jewish Labour Movement (@JewishLabour) June 27, 2019