Alan Dershowitz, the prominent US lawyer and pro-Israel activist, has vowed to campaign against Jewish candidate Bernie Sanders should he win the Democratic Party nomination for president.

Prof Dershowitz accused the Vermont senator of having “endorsed” Jeremy Corbyn for the UK “Prime Ministership”, describing the Labour leader of being “one of the men who has most promoted and tolerated antisemitism in England and in Europe”.

He made the comments in an interview on Larry King’s Politicking talk show.

When challenged by Mr King, who said he had never heard Mr Sanders make an antisemitic comment, Prof Dershowitz responded that “some of the worst people in terms of not promoting Jewish values are Jews”.

He added: “That’s no excuse. Karl Marx was a Jew, at least a Jew by heritage. So that’s no excuse.”

Mr Sanders did not endorse Mr Corbyn in the 2019 general election, and has not publicly backed him since doing so in 2017.

He will contest the Iowa caucus this week – the first of 50 primary elections in the race for his party’s nomination for president.

An early frontrunner, Mr Sanders is hoping to become the first Jewish president of the United States.

Prof Dershowitz, a renowned expert on criminal and US constitutional law, has received negative media attention in recent years for his previous association with Jeffrey Epstein.