“Israel the new Nazi state,” “One Holocaust does not justify another” and “Netanyahu surpasses Hitler in barbarism” were among the slogans on placards held aloft by participants in Saturday’s pro-Palestinian rally in central London.

Another banner showed a depiction of Jesus carrying the cross, accompanied by the words: “Do not let them do the same thing today again”. It prompted David Baddiel to tweet: The way to spot if anti-Zionism is blurring into antisemitism is to keep your eye out for the age-old tropes: the ones that existed a long, long time before 1948. And they don’t come much more age-old and recognizable than this one.”

Protesters in London defaced Israeli flags and there were calls for a boycott of Marks & Spencer - the “Israeli embassy on the high street”.

Speakers at the rally included Jeremy Corbyn and former Shadow Chancellor John McDonnell, the latter saying he welcomed the ceasefire but added that there would be no ceasefire “in our campaign to boycott, disinvest and sanction the Israeli apartheid state”.

Politicians and anti-racism campaigners condemned the anti-Jewish hate expressed during the event – which organisers claim attracted up to 180,000 supporters.

The government’s antisemitism czar Lord John Mann told the Sunday Times: “The disgusting racist abuse against Jewish people on the streets of London requires an effective and strong response by all politicians and will be treated with contempt by all decent citizens.”

Labour MP Dame Margaret Hodge said that failure to distinguish between Jew hatred and the Palestinian-Israel conflict “is a cause of antisemitism that we have to call out and stop”.

Metropolitan Police said that seven men were arrested during the protest. Three of the arrests were for violent disorder, two for going equipped to steal, one for a racially aggravated public order offence and another for a homophobic public order offence.

Protests also took place in other Manchester and other UK cities.