Academics heading for their annual congress this week were warned by their leaders that any call for a boycott of Israel would be declared null and void.

Half a dozen motions of varying degrees of hostility towards Israel were tabled for debate on today (Wednesday afternoon) on the first day of the congress of the University and College Union in Bournemouth.

But the union’s executive warned that two of them could bring legal repercussions by targeting Israeli institutions.

One resolution, from the union’s north-west regional committee, urged support for “the Palestinian call for a boycott, disinvestment and sanctions (BDS) campaign”.

A second, proposed by the University of Brighton Grand Parade, College of North East London and East London University, sought a conference of BDS supporters to investigate action against Israel “including an option of institutional boycotts”.

It also called on members “to reflect on the moral and political appropriateness of collaboration with Israeli educational institutions”.

Both were published in the congress agenda with an explicit warning from the union’s executive, saying that it had received legal advice that to pass the motion “would be unlawful because it is likely to be viewed by a court as a call to boycott Israeli academic institutions”.

The caveat continued: “The union has previously followed advice from leading counsel that such a call would be outside the powers of the union to make”.

If the motion were passed unamended, the president Sasha Callaghan “has been advised that she will have to treat it as being void and of no effect”, delegates were told.

In 2007 the union abandoned moves to boycott Israeli universities after being told that this could be in breach of laws against racial discrimination.

But the following year the congress reignited the controversy, leading to fresh threats of legal intervention after it passed a motion urging academics “to consider the moral and political implications of educational links with Israeli institutions”.

Lorna Fitzsimons, who jointly chairs the Stop the Boycott Campaign with Jeremy Newmark, said in advance of this week’s meeting: “It is extraordinary that such a potentially important union seems unable to grasp the concept that the rest of the world… is trying to build bridges and make peace whilst they continually attempt to isolate, alienate and polarise the Israeli educational establishment. Anybody who has had any involvement with Israel’s academia will know of their historic role in Israel’s constant attempt to strive for peace.”