Sir Keir Starmer has denied he is targeting left-wingers within Labour after Diane Abbott had the whip suspended following comments about racism.
The Hackney North and Stoke Newington MP suggested Jewish, Irish and Traveller people are not subject to racism “all their lives”.
It comes weeks after the National Executive Committee backed a proposal from Sir Keir not to endorse former leader Jeremy Corbyn to contest Islington North for Labour at the next election.
Ms Abbott said in a letter in The Observer that although white people “with points of difference” experience prejudice, they do not suffer the same racism as black people.
Appearing on Jeremy Vine’s BBC Radio 2 show, Sir Keir rejected any suggestion that he was trying to get rid of left-wingers.
“I was very clear, I think it was the first thing I said as Labour leader, which was I would tear antisemitism out by its roots from our party.
“And I asked all those that had lost confidence in Labour because of antisemitism to judge me by my actions, not by my words.
“In both of those cases, Jeremy and Diane, it’s an antisemitism issue.
“And I make no apologies for the fact that we are changing and have changed our party.
“And I think in the end, what they say speaks for itself.
“There aren’t many people going out saying that it’s possible to defend what Diane Abbott said last weekend. Most people including Diane, who of course apologised, recognised just how wrong and offensive it was.”