Keir Starmer has said he does not want a “civil war” in Labour, after Jeremy Corbyn was suspended from the party.
But the Labour leader said his predecessor could yet be expelled and accused him of adding to the “pain” of the Jewish community.
Supporters of Corbyn have rallied to his defence after a damning investigation into Labour’s handling of anti-Semitism during his time as leader.
The report by the Equality and Human Rights Commission (EHRC) found the party was responsible for unlawful acts of harassment and discrimination.
But Corbyn rejected some of the equality watchdog’s findings and claimed the issue had been “dramatically overstated for political reasons” by his critics.
This put him at odds with Starmer and led to Corbyn having the whip removed on Thursday.
Speaking to BBC Radio 4′s Today programme on Friday, Starmer said he was not gong to “renege” on his commitment to tackle anti-Semitism.
“I don’t want a civil war in the Labour Party, I don’t think there is any need for one,” he said.
Asked if Corbyn could face permanent expulsion, Starmer said it was not his decision to make, but added: “Yes, people have been expelled from the Labour Party.
“It’s not for me to say what process should be followed,” he added. “Or what sanction is in order.”
Starmer said Corbyn’s decision not to accept the EHRC report in full “just adds to that pain” felt by “Jewish communities and Jewish members”.
Unite union boss Len McCluskey called Corbyn’s suspension an “act of grave injustice” which could “create chaos within the party” and put any chance of election success in jeopardy.
Ex-shadow chancellor John McDonnell described the suspension as “profoundly wrong”.
Momentum, the campaign group that helped propel Corbyn to the party leadership, announced there will be a virtual Stand with Corbyn rally on Friday evening.
“The suspension of Jeremy Corbyn by the Labour Party leadership is a naked attack on the left that undermines the fight against anti-Semitism and makes a mockery of Keir Starmer’s pledge to unite the party,” it said.
The fallout came on what Sir Keir labelled a “day of shame” for Labour after the EHRC found the party broke equality law over its handling of anti-Semitism complaints.
The EHRC investigation found evidence of “political interference” by then leader Corbyn’s office in the complaints process.
Interim chair Caroline Waters said there had been “inexcusable” failures which “appeared to be a result of a lack of willingness to tackle anti-Semitism rather than an inability to do so”.
The watchdog identified three breaches of the Equality Act relating to political interference in complaints, failure to provide adequate training to those handling anti-Semitism cases, and harassment.
This article originally appeared on HuffPost UK and has been updated.