Ken Livingstone has been suspended from the Labour Party and is unable to hold office for another year following his controversial comments about Adolf Hitler and Zionism.
But what provoked this punishment and what is the reaction to it?
What did he say?
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The row began last year, when the former London mayor defended MP Naz Shah against accusations she had sent anti-Semitic messages on social media.
It emerged last April that in August 2014, Shah shared a Facebook post supporting political scientist Norman Finkelstein's proposal to relocate Israel to the US. The MP also commented that she would send the idea to Barack Obama and David Cameron as it might "save them some pocket money".
In a BBC interview about the row that followed the reporting of these comments, Livingstone said Shah had been "rude and over-the-top", but added there was a "well-orchestrated campaign by the Israel lobby to smear anybody who criticises Israeli policy as anti-Semitic".
He continued: "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."
What is Zionism?
Zionism refers to the movement to create a Jewish state in the Middle East, which is now Israel.
Livingstone's comments suggested that at some stage Hitler held positive views towards Jews, a view Rabbi Dr Jonathan Romain, from Maidenhead Synagogue, says is a "deliberate falsification of history".
He adds: "Saying Hitler is a Zionist is… akin to describing the Yorkshire Ripper as a nice family man."
What was the reaction?
Almost immediately after Livingstone's comments, Labour MP John Mann, chairman of the all-party parliamentary group against anti-Semitism, was filmed confronting him on the stairs at the BBC's offices in Millbank, calling him a "f****** disgrace" and a "Nazi apologist".
Labour leader Jeremy Corbyn said: "We will not tolerate any anti-Semitism in the party," while Sadiq Khan, then running for London mayor, called for Livingstone to be kicked out of the party.
Livingstone was suspended on 28 April 2016, pending an investigation.
Labour itself was subsequently the subject of large-scale scrutiny by the media, with The Guardian declaring that "Labour and the left have an anti-Semitism problem".
What happened next?
After a three-day hearing, a disciplinary panel this week found Livingstone to have breached party rules on three occasions relating to the row and he was formally suspended for a year.
"I expected them to expel me, so I've now got to consider whether I challenge this legally or just live with it," he said, adding that the experience was like "sitting through a court in North Korea".
He also claimed once again that he was being disciplined "for stating a historical truth" and that he would launch a campaign to overturn the suspension, says the BBC.
What is the reaction to the new ruling?
Labour's decision to only suspend Livingstone instead of expelling him has drawn the ire of many in the political sphere.
"I'm very upset with the party's attitude, I do not believe there has been a zero tolerance policy towards anti-Semitism," Jewish Labour peer Lord Levy told BBC Radio 4's Today programme.
He added that Corbyn was "a failed leader who is not leading our party forward as a serious opposition party".
Former leadership candidate David Miliband described the situation as "an unspeakable state of affairs", adding: "There should never be a day when those words anti-Semitism and Labour end up in the same sentence."
Chief Rabbi Ephraim Mirvis also criticised the decision. Labour had "yet again failed to show" that it was "sufficiently serious about tackling the scourge of anti-Semitism", he said.
"The Labour Party has failed the Jewish community, it has failed its members and it has failed all those who believe in zero tolerance of anti-Semitism."
