The Labour Party has suspended Ken Livingstone from holding office for another year over comments he made about Adolf Hitler and Zionism.
A disciplinary panel upheld three charges of breaching party rules.
The ex-London mayor has been suspended since April 2016 when he claimed Hitler had supported Zionism in the 1930s.
Some Labour MPs and Jewish groups have criticised the decision not to expel Mr Livingstone, but he said he had been "suspended for stating the truth".
The row first erupted when Mr Livingstone, who was defending MP Naz Shah over claims she had made anti-Semitic social media posts, said: "When Hitler won his election in 1932, his policy then was that Jews should be moved to Israel. He was supporting Zionism before he went mad and ended up killing six million Jews."
He has repeatedly defended his version of events, saying there had been "real collaboration" between Nazis and Zionists before World War Two.
Following the disciplinary hearing, Labour said Mr Livingstone had breached its rule 2.1.8, which says 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".
He has been suspended from standing for office or representing the party at any level for two years, although he remains a party member.
The suspension will expire in April 2018 taking into account the suspension he has already served. The party said it would make no further comment.
Speaking outside the hearing, Mr Livingstone said he was not planning on running for office so the suspension "doesn't make a great deal of change", and said the hearing had been "like sitting through a court in North Korea".
A statement released by his office said he would be launching a campaign to overturn the suspension, adding that the hearing "was not in accord with natural justice" because it was held in private.
Speaking on BBC Newsnight, he said "if anyone is upset by what I said of course I apologise" but added he would not apologise for something he did not say.
Labour MP Wes Streeting told Mr Livingstone he would not be welcome in his constituency, telling him: "Your poor judgement, your crass remarks and your lack of apology brings the Labour Party into disrepute."
Another Labour MP, Michael Dugher, said he should be "kicked out for good", and Luciana Berger said the "appalling decision" marked a "new low" for the party.
Anti-Semitism and Zionism
- Anti-Semitism is "hostility and prejudice directed against Jewish people" (OED)
- Zionism refers to the movement to create a Jewish state in the Middle East, corresponding to the historic land of Israel - anti-Zionism opposes that
- Some say "Zionist" can be used as a coded attack on Jews, while others say the Israeli government and its supporters are deliberately confusing anti-Zionism with anti-Semitism to avoid criticism
The president of the Board of Deputies of British Jews, Jonathan Arkush, said: "Relations between the Labour Party and the Jewish community have reached a new all-time low.
"After 12 months of indecision, despite finding him guilty of all three charges, the Labour Party has decided to suspend him from holding office for just one year despite his shameless, disgraceful and tendentious attempts to link Zionism to Nazism."
Holocaust Educational Trust chief executive Karen Pollock said it was a "slap on the wrist for a serial offender", and Simon Johnson, chief executive of the Jewish Leadership Council, said he should have been expelled for his "inaccurate and antagonistic comments".
The Jewish Labour Movement has promised to raise the matter at Labour's annual conference in September if Mr Livingstone is allowed to stay in the party.
Labour's shadow attorney general, Baroness Chakrabarti, who carried out an inquiry into allegations of anti-Semitism in the party before being made a peer by Labour leader Jeremy Corbyn, said: "I hope people might now revisit my report and remind themselves of better ways to argue about difficult issues without compromising our values of solidarity, tolerance and respect."