A huge anti-Israel banner was unfurled outside Parliament by pro-Palestinian protesters on Wednesday.
The protest, organised by Led by Donkeys, the political campaign group, saw the 40 x 40-metre banner, reading: “Yes it’s a genocide,” laid out in Parliament Square.
The Metropolitan Police said the demonstration had finished and there had been no arrests.
In a statement to coincide with the protest, Prof Amos Goldberg, an Israeli history professor, said: “Yes, it’s a genocide. And once you come to this conclusion, you cannot remain silent.
“It does not need to look like the Holocaust to be a genocide. Each genocide looks different, and not all involve the killing of millions or the entire group.
“The United Nations Genocide Convention explicitly asserts that genocide is the act of deliberately destroying a group in whole or in part. Those are the words. But there does need to be a clear intent.”
Prof Goldberg said the Israeli government, military and media had shown “clear indication of intent to destroy Gaza”.
Nigel Farage, the Reform UK leader, said the protesters “should have been stopped”, while Richard Tice, his deputy, added: “Imagine how long a similar poster saying ‘Israel can defend itself’ would last.”
Greg Smith, the Tory MP for Mid Buckinghamshire, said: “There is legitimate protest, and then there is this – utterly offensive and wrong.”
At the weekend, supporters of Israel confronted pro-Palestinian marchers in London for brandishing signs that compared the conflict in Gaza to the Holocaust.
Such signs and placards have been condemned as anti-Semitic for minimising the unique nature of the Holocaust and playing on anti-Jewish tropes.
Counter-protesters from Stop Hate UK gathered near Piccadilly Circus, in central London, along the route of the National Demonstration for Palestine, urging those taking part to “stop supporting terror”. Police kept the two sides apart as the march made its way towards Whitehall.
The Palestine Solidarity Campaign, which helped organise Saturday’s march, has said Britain is complicit in what it describes as “Israel’s genocide and apartheid” of Gaza.