Allies of Jeremy Corbyn have reacted with fury at the decision to block him from returning as a Labour MP.
The former Labour leader was told on Wednesday morning that he won't have the party's whip restored, despite his suspension from Labour being lifted by a disciplinary panel.
It means that Mr Corbyn will still not officially be a Labour MP - and will continue to sit as an independent MP in the House of Commons - even though he has been reinstated as a party member.
Current Labour leader Sir Keir Starmer said he would continue to withhold the whip from Mr Corbyn because his predecessor had "undermined" the party's efforts to restore confidence in its ability to tackle antisemitism.
It follows Mr Corbyn's response last month to a damning report by the Equalities and Human Rights Commission into Labour's handling of antisemitism claims under his leadership.
Those Labour MPs supportive of Mr Corbyn have been left angered by Sir Keir's action.
John McDonnell, Mr Corbyn's long-time ally and Labour's former shadow chancellor, said the decision to continue to withhold the whip was "just plain wrong & will cause more division and disunity".
"Jeremy's gone through the formal procedures & decision has been made properly," he added on Twitter.
"I appeal to everyone that surely it's time to move on & start working together to implement the EHRC."
Diane Abbott, Labour's former shadow home secretary, tweeted: "Labour MPs lose the whip if suspended from the party automatically.
"De facto you can't be a Labour MP if you're not actually in the Labour Party.
"But removing the whip from @jeremycorbyn now raises serious questions of due process."
And Richard Burgon, another who served in Mr Corbyn's shadow cabinet, said: "Jeremy Corbyn has rightly been reinstated to the Labour Party.
"That decision must be respected & implemented across the Labour Party.
"Jeremy should immediately have the whip restored. At a time of national crisis, division in the Labour party serves nobody but the Tory Gov't."
Meanwhile, the Momentum group - who supported Mr Corbyn during both his Labour leadership campaigns - branded Sir Keir's decision "a joke".
"A disciplinary panel found that Corbyn broke no rules - so now Starmer is making it up as he goes along," their official Twitter account tweeted.
Momentum also urged supporters to sign a petition, which soon attracted more than 1,500 signatures, calling for Mr Corbyn to have the whip restored.
Jon Lansman, the founder of Momentum, accused Sir Keir of having "driven a coach and horses through the party's disciplinary process, making it subservient to the parliamentary party and embedding 'political interference'".
However, other Labour MPs voiced their support for Sir Keir's decision.
Dame Margaret Hodge, who Sir Keir spoke to on Tuesday night, said: "As Corbyn has refused to himself accept the findings of the EHRC report, refused to apologise for his actions and refused to take any responsibility, withholding the whip is the right decision."
Neil Coyle said that continuing to withhold the whip from Mr Corbyn was the "only option" until a new independent complaints process was established.
The president of the Board of Deputies of British Jews, Marie van der Zyl, said Labour's disciplinary process was "clearly still not fit for purpose" but Sir Keir had "taken the appropriate leadership decision not to restore the whip to Jeremy Corbyn".
Sir Keir has left the door open for Mr Corbyn to rejoin the Parliamentary Labour Party by saying the situation would be kept "under review".
But his spokesman would not detail any of the steps needed for him to rejoin.
"I'm not going to pre-empt any of that," the spokesman said, when asked if a clear retraction and an apology by Mr Corbyn would be sufficient.