Ed Miliband has become the latest senior shadow cabinet figure to back the firing of Rebecca Long-Bailey from Labour’s frontbench for sharing what he deemed to be an antisemitic conspiracy theory. The Labour leader, Keir Starmer, sacked his shadow education secretary and Jeremy Corbyn supporter after she commented on an interview with the actor Maxine Peake. Following the death of George Floyd, Peake claimed Israeli forces had taught Americans how to restrain people with a knee on the neck. Long-Bailey’s sacking has ignited a vicious online row within the party. The general secretary of the Unite union, Len McCluskey, said it was an overreaction in a “confected row” and risked disuniting the party. The Momentum campaign group boss, Jon Lansman, who is Jewish, said he did not believe the remark by Peake was antisemitic. Peake later said she was sorry for being inaccurate. Long-Bailey, who ran as Corbyn’s heir in the leadership election, said she had not endorsed all parts of the article and had shared it because it was about the Tory response to coronavirus. Miliband, the shadow business secretary and a former party leader, said Long-Bailey was a decent person and not antisemitic but that Starmer was right to sack her. The reason the Maxine Peake interview was a problem “is not that it had a criticism of the state of Israel. I’m a big critic of what the Israeli government has done on a number of occasions. It was that it was a false criticism of the state of Israel, or rather the Israeli Defence Force, linked to the death of George Floyd, wrongly, saying that somehow tactics that killed George Floyd were linked to the Israelis,” Miliband told the BBC’s The Andrew Marr Show. “The problem is that over the centuries when calamitous things have happened, Jews have been blamed. That’s why there’s an antisemitism issue in relation to this and that’s why I believe Keir took the right decision. I think she made a significant error of judgment.” He said the move indicated Starmer was determined to get on top of the issue of antisemitism within Labour and it could not become a discussion point at the next general election. There have, however, been claims from those who backed Long-Bailey for the leadership that it was a factional move, and some members have threatened to quit the party. The shadow work and pensions secretary, Jonathan Reynolds, defended Starmer’s move. The Stalybridge and Hyde MP told Sky News’s Sophy Ridge on Sunday show that the sharing of an antisemitic conspiracy theory was not something that could be ignored. “We deserve no more chances with the Jewish community to win back the trust that has been lost,” he said. “Keir promised zero tolerance and that has to mean zero tolerance. And I’m afraid for that reason that change had to be made.” He said he worried deeply that people were still unable to understand why an article like that might have been offensive to Jewish people. “Throughout time there has been an antisemitism that has been about blaming Jewish people for all the problems in the world. A modern incarnation of that is replacing Jews with Israel,” he said. “If someone is looking at the terrible scenes in America and somehow trying to change the blame to Israel, the antisemitic warning lights should be flashing to anyone who sees that in print or hears something like that.”