A leading scientist has resigned from the University and College Union after accusing the organisation of being "institutionally antisemitic".
Denis Noble, who is not Jewish, said he took the decision after almost 50 years as a member of the union because it had become "impossible" for him to continue, given the "punishment of Israeli colleagues for the actions of their government".
Professor Noble is an eminent biologist who was chair of cardiovascular physiology at Oxford University for 20 years. In 1960 he developed the first model of the working heart. His resignation has been backed by fellow Oxford scientists Michael Yudkin and David Smith. They also resigned, saying it was "beyond dispute that UCU is now institutionally antisemitic".
UCU general secretary Sally Hunt insisted the union was "not an antisemitic organisation," but added the resignations were a "cause for concern".
Elements in UCU have tried unsuccessfully for more than three years to introduce an academic boycott of Israel, provoking harsh criticism of the organisation from Jewish lecturers and pro-Israel groups.
In his resignation letter to Ms Hunt, Prof Noble pointed out he had first written to her more than a year ago, making clear his objections to the UCU conference's "discrimination against Israeli colleagues", but had not received a reply.
"Nobody in the world of learning can take seriously a professional organisation that purports to represent academic staff, but which entertains proposals to discriminate whether it be on grounds of sex, race, national origin or other characteristics that are irrelevant to academic excellence."
Prof Noble said: "I find it impossible not to ask myself why UCU exhibits this obsession with Israel. The obvious explanation - that the union is institutionally antisemitic - is so unpleasant that I have till recently been unwilling to accept it."
But Ms Hunt said: "UCU does not endorse an academic boycott of Israel and our position of opposition to the occupation is, far from being extreme, in line with that of the TUC."