Academic Friends of Israel has warned that the forthcoming University and College Union general secretary election is unlikely to lead to any alteration of the union's stance on Israel.
Incumbent Sally Hunt faces competition for the role from Socialist Workers' Party member, Mark Campbell.
Mr Campbell is a founder member of the increasingly influential UCU Left caucus which is dominated by SWP members. He works as a lecturer in computing at London Metropolitan University.
AFI director Ronnie Fraser said UCU members worried about the union's stance on Israel during Ms Hunt's time in charge now faced a choice which would put them "between a rock and a hard place".
He wrote to AFI supporters: "One thing is clear - over the next five years, regardless of who becomes general secretary, the union's fixation with Israel is likely to continue as the UCU Left faction shows no sign of losing control of the NEC."
The union has adopted 16 anti-Israel resolutions during Ms Hunt's leadership, is affiliated to the Palestine Solidarity Campaign, and supports the boycott, divestment and sanctions campaign against Israel.
Mr Fraser said the union would not accept it had become "institutionally racist". This has a bigger impact than one first realises because more Jews in the UK today belong to the teaching unions than any other trade union," he said.
Ballots for contested positions opened earlier this month and will close on Thursday, March 1. Elections will also be held to elect half of the union's national executive committee. UCU has more than 120,000 members.
Mr Fraser is taking legal action against UCU over his belief it breached equality legislation with its rejection of the widely-accepted definition of antisemitism. His case is expected to be heard this autumn.
Communities Secretary Eric Pickles warned last June that UCU's rejection of the definition sent a "chilling message" to Jewish academics and students and that UCU believed Jews were "fair game for invective".