39 Labour MPs, including the party's London mayoral candidate and four members of Labour's frontbench, have called for Ken Livingstone to be suspended from the party after he made a series of inflammatory comments on Wednesday and Thursday.
BuzzFeed News understand that shadow Welsh secretary Nia Griffith is furious Labour leader Jeremy Corbyn hasn't acted faster to suspend Livingstone, considering local and regional elections are taking place in seven days, and plans to call the leadership's and demand Ken is suspended pending a full investigation.
Speaking to BBC Radio London on Thursday morning, the former mayor of London said it was no longer possible to criticise Israel without facing accusations of anti-Semitism.
He added: "Hitler was supporting Zionism – this before he went mad and ended up killing 6 million Jews."
Livingstone also repeated assertions he first made on Wednesday that he had never heard any Labour members ever make any anti-Semitic remarks.
He was speaking after Labour MP for Bradford West Naz Shah was suspended from the party after she shared a series of anti-Semitic posts on Facebook.
Livingstone told BBC Radio London Shah was suspended because of a "well-orchestrated campaign by the Israel lobby to smear anyone who criticises Israeli policy as anti-Semitic".
Labour's current London mayoral candidate, Sadiq Khan, has called on action to be taken against Livingstone. "There must be no place for [these comments] in our Party," Khan said.
The leader of Scottish Labour Kezia Dugdale agreed with Khan. There's "no place for this in any party," she said.
Jess Phillips was more direct and called for the party to suspend Livingstone immediately.
Her sentiments were also echoed by Labour MPs John Woodcock, who said Livingstone should "actively be seeking suspension" after the remarks, Wes Streeting, who said Livingstone has "form on antisemitism and has been tolerated for far too long", and Conor McGinn, who said the party "can't allow this to go on".
Michael Dugher, who was sacked from the shadow cabinet by Corbyn in January, pointed out that shadow chancellor John McDonnell has previously said: "If people express antisemitic views, there's no room for them in our party and I'd like them out of our party for life, to be frank."
Jon Lansman, a close ally of Corbyn, has said Livingstone should resign. "It's time he left politics altogether," he said.
The Jewish Labour Movement has also called on Livingstone to be suspended. "He has had a free pass on offending Jews for too long," Jeremy Newmark, the group's chair said. "No place for such views on the party NEC."
Labour's shadow mental health minister tweeted an example of anti-Semitic abuse she receives on Twitter.
A spokesperson for Jeremy Corbyn did not respond to request for comment.
This is the full list of Labour MPs who have now called on Ken Livingstone to be suspended by the party: