The pair are planning to publish a paper outlining their objections to a pro-boycott motion passed by British academics last month and Mr Dershowitz has threatened to "devastate and bankrupt" those he believes are acting against Israeli universities.

Members of the University and College Union passed a motion at their annual conference instructing leaders to circulate calls for a boycott of Israeli institutions to every UK campus for "information and discussion".

Yesterday Mr Julius, who has had a string of high-profile clients and is visiting professor at Birkbeck College, said the UCU's decision had sparked widespread anger. "People are pretty appalled at their stance, what they see are double standards when it comes to Israel," he said. "The majority of Jews find this repellent and many academics reject the pitiful arguments which have been put forward and which do not reflect well on the state of academic work in this country."

Mr Dershowitz, the prominent lawyer and Harvard law professor who is well known for the ferocity of his attacks on those he perceives as enemies of Israel, told the Guardian that if the boycott call is endorsed by the UCU branches there would be retribution, and that he had enlisted 100 lawyers to break the boycott.

"If the union goes ahead with this immoral petition, it will destroy British academia," Mr Dershowitz said. "We will isolate them from the rest of the world."

Yesterday supporters of an academic boycott said they were determined to press ahead with the campaign.

Sue Blackwell, who spoke in favour of the motion at the union conference last month, said: "We have voted to discuss how best to help our Palestinian brothers and sisters who often are not allowed to get to college or university and that is what we will do."

She said the proposed boycott had sparked a renewed debate about the plight of the Palestinians since it was first raised five years ago.

"This is about boycotting institutions about criticising the policies of the Israeli government not about individuals."