Ken Livingstone will face a new investigation into his comments claiming that Hitler supported Zionism, it emerged this afternoon, as Jeremy Corbyn hit out against his old ally for refusing to apologise and causing deep offence to the Jewish community.

Labour's ruling body will now launch a fresh disciplinary process against Livingstone, who was suspended from the party for a further year but controversially not expelled over his original comments made in April 2016.

Corbyn, the Labour leader said: 'Ken Livingstone's comments have been grossly insensitive, and he has caused deep offence and hurt to the Jewish community.

'It is deeply disappointing that, despite his long record of standing up to racism, Ken has failed to acknowledge or apologise for the hurt he has caused. Many people are understandably upset that he has continued to make offensive remarks which could open him to further disciplinary action.

'Since initiating the disciplinary process, I have not interfered with it and respect the independence of the party's disciplinary bodies. But Ken's subsequent comments and actions will now be considered by the national executive committee after representations from party members.'

Earlier, the Labour Party was accused of 'failing the Jewish community' over its failure to expel the former London mayor.

Livingstone was suspended for two years from the party on Tuesday for saying Hitler supported Zionism when he was elected in 1932 before 'he went mad and ended up killing six million Jews'.

The Chief Rabbi, Ephraim Mirvis said the decision not to expel him fully 'yet again failed to show' the party was 'sufficiently serious about tackling the scourge of anti-Semitism'.

But Livingstone has said he will fight to overturn the ban.

Tom Watson, Labour's deputy leader, also attacked the internal party ruling and said he 'can't disagree' with the Chief Rabbi.

Labour's internal disciplinary panel upheld three charges against the former mayor and said he contravened the rule that 'no member of the party shall engage in conduct which in the opinion of the NEC is prejudicial, or in any act which in the opinion of the NEC is grossly detrimental to the party'.

But it stopped short of expelling him and simply barred him from standing for office or representing the party at any level for two years.

Jeremy Newark, chair of the Jewish Labour Movement, said the ban was 'quite insufficient'.

He said: 'It seems the party is operating some kind of revolving door policy where one can make deeply hurtful and offensive comments, denies the history of the Holocaust, and dip in and out of party membership.

'It's a betrayal of the values of our party and what it stands for.

'I feel they've fudged an incredibly important and significant decision, a moment that could have been a turning point for the Labour Party in proving that it has zero tolerance for anti-Semitism appears to have been wasted.'

Joe Glasman, head of political and government investigations at Campaign Against Antisemitism, said: 'Ken Livingstone has been portraying Jews as Nazis for decades. His claim that Hitler acted in support of Zionism, along with his constant repetition of that distortion, has been a repulsive spectacle.

'We felt sure that the Labour Party, blighted by antisemitism as it is, would reclaim some of its former self and expel him. Labour has long had a moral duty to expel Ken Livingstone, but instead it has allowed his vile views to gain support in the Party.

'Today's verdict confirms our worst fears: that it is possible to husband and broadcast such repellant beliefs and still remain a Labour Party member has shocked even us. This surely represents the last of the death throes of the Labour Party's long relationship with the Jewish community. The Labour Party had this one last chance to prove that it is not beyond salvation. Today's decision is the Party's final act of brazen, painful betrayal.'