Sir Keir Starmer has said there is "no need for a civil war" in the Labour Party but remains "disappointed" in his predecessor Jeremy Corbyn's comments after a damning investigation into its handling of anti-Semitism.
He told ITV News' Political Reporter Shehab Khan: "There is no need for a civil war here, I certainly don't want a civil war, the outcome yesterday was not the outcome that I was looking for."
Sir Keir said he wanted to be able to "draw a line in the sand and move forward as a united party tackling anti-Semitism", but his predecessor hindered that.
Mr Corbyn was suspended after he refused to retract his claim that the scale of anti-Semitism in Labour had been "dramatically overstated for political reasons" by his critics.
His comments put him at odds with his successor and led to him having the whip removed on Thursday.
A report by the Equality and Human Rights Commission (EHRC) found the party was responsible for unlawful acts of harassment and discrimination.
Since then, Labour splits have begun to emerge as left-wing supporters rallied to Mr Corbyn’s defence following his suspension from the party.
When asked about the split in the Labour Party, Sir Keir said: "I think the vast majority of our members and supporters were shocked by the findings yesterday and are completely behind me in my determination to root out anti-Semitism."
He said: "Look, I regret the findings, I regret that the Labour Party, which passed the equalities legislation in the first place, and set up the Human Rights Commission, is found to be in breach of it - that is why I apologised."
Sir Keir added: "I don't want the Labour Party and anti-Semitism in the same sentence ever again."
But allies of Mr Corbyn have criticised the decision and warned it risked opening up splits.
Unite union boss Len McCluskey called it an "act of grave injustice" which could "create chaos within the party" and put any chance of election success in jeopardy.
"A split party will be doomed to defeat," he said.
Mr McCluskey added: "Obviously this is a sensitive time. I thought it was wrong what's happened.
"But now is the time for some calmness so that we can see if we can resolve this."
The Unite boss added: "Yesterday should have been about moving on from anti-Semitism and embracing what the EHRC said, which Keir did.
"Unfortunately now, we've all been knocked off the rails a little bit by Jeremy's suspension.
"I think it was unjust and hopefully with discussions that can take place we can resolve it and we can all move on."
Mr McCluskey also urged "hundreds of thousands" of Labour members to stay in the Party.
He said: "I'm hoping that we're hoping to resolve the matter. My message really to literally hundreds of thousands of our members who are already expressing their anger is to stay in the Party."
Mr McCluskey added: "We need the party to be united. Working people out there need us, need a Labour government.
"Stay in the Party and I'm hoping we'll be able to get through this fairly quickly to everybody's satisfaction."
When asked about McCluskey's criticism, Sir Keir said: "I've spoken to Len McCluskey and I don't think for one minute that Len McCluskey wants to see a split in the Labour Party."
He added: "I stood as leader of Labour Party on the basis of uniting the party and I will make good on that pledge - but I also said that I would root out anti-Semitism.
"That requires difficult decisions and I am not going to duck difficult decisions where I have made a commitment as a matter of principle to root out anti-Semitism."
Speaking on Thursday, the former party leader said he was "very shocked and disappointed" after the party announced he would have the whip removed.
Mr Corbyn said: "I've been in the Labour Party all my life. I want to make it very clear: anti-Semitism has no place whatsoever in our party or our movement.
"I've opposed it and racism in all its forms for all my life."
Labour has committed to proper training, with the EHRC recommending it should be mandatory and fully implemented within six months.
Recommendations made by the watchdog include commissioning an independent process to handle anti-Semitism complaints.
The EHRC’s lead investigator Alasdair Henderson told a press conference that blame could not be placed on one person alone and the problem went beyond Mr Corbyn, but added that “as leader of the party, and with evidence of political interference from within his office, he does have a responsibility ultimately for those failings”.
The Jewish Labour Movement said blame for the “sordid, disgraceful chapter” in the party’s history “lies firmly with those who held positions of leadership”.
Chief Rabbi Ephraim Mirvis said the report was a “historic nadir for the Labour Party”.