Labour has demonstrated a “breathtaking” lack of humanity by failing to understand the impact antisemitism had on the party, Sadiq Khan has said.

The London mayor said in an interview that Jewish friends of his said they had not voted for Labour because they viewed it as racist.

He told the Sunday Times the party needed more change than just to its leaders: “It’s not just about changing the lead singer, it’s the whole band. The music was wrong.

“For the leadership not to understand the impact of us being seen to condone antisemitism is heartbreaking. We’ve demonstrated a breathtaking lack of emotional intelligence — or humanity.”

Mr Khan said his Jewish friends who did not vote for the party were correct on racism: “It’s a disqualification to be Labour leader if you don’t understand it and don’t have a clear plan to address it.”

Members with antisemitic views needed to be expelled and quickly, he continued.

“You’ve got to. If someone takes us to court, so be it. The ease with which Alastair Campbell was chucked out for talking about voting for another party, and yet you have antisemites still in, beggars belief.”

Ken Livingstone, Mr Khan’s predecessor as London mayor, was a clear case: “He said things that were clearly antisemitic. He remained a Labour member for two years until he quit. He wasn’t kicked out.”

Racism and antisemitism became “normalised” if they are not addressed at their roots, he told the newspaper, adding: “It is toxic. I met decent people who said, ‘It’s a bit smelly, this antisemitism stuff,’ and they didn’t vote for us.”

He said he was tired of the “whataboutery” used in Labour’s defence: “Sure, the Tories may be Islamophobic. That doesn’t concern me. The standards I expect from Labour are higher than other parties.”