THOUSANDS backed a petition yesterday calling on Labour MP John Mann to be disciplined for launching into a “toxic” rant at Ken Livingstone.

In a twist to the sorry saga, more than 10,000 backed the suggestion after Mr Mann (pictured) called the former London mayor a “disgusting nazi apologist.”

However petitioners called Mr Mann’s behaviour “appallingly unprofessional and toxic,” adding that “regardless of the argument the harassment was totally opportunistic and beyond reprehensible.”

The petition, which will be delivered to Labour leader Jeremy Corbyn, states: “You are not at liberty Mr Mann to single-handedly bring the Labour party into disrepute.”

Labour may change its rules to ensure a “zero-tolerance” approach to anti-semitism following the ongoing row, that has seen the suspension of an MP and former London mayor Ken Livingstone.

Party deputy leader Tom Watson said yesterday Labour’s structures could be changed to send a “clear signal” that the problem was being addressed.

MP Naz Shah was suspended for supporting an anti-semitic Facebook post before she became Bradford MP.

Mr Livingstone was suspended yesterday for mounting a defence of Ms Shah in which he argued Hitler had supported zionism “before he went mad and ended up killing six million Jews.”

West Brom MP Mr Watson said the comments which led to the suspension of Mr Livingstone verged on anti-semitism and were certainly “offensive and provocative.”

He said the party’s ruling National Executive Committee would decide on his fate but that “no-one is in any doubt” that he “let down the Labour Party.”

Among the measures mooted were a more rigorous vetting procedure for potential candidates and examining whether the party’s rules on such issues were “robust” enough Mr Watson said.

It was now for the executive to decide whether to expel Mr Livingstone from the party, he added.

Mr Livingstone insisted yesterday that the internal inquiry would have to exonerate him as “it’s hard for somebody to decide to suspend me” after 30 years of making the same point.

“How can the truth be an offence?” Mr Livingstone asked.