In a debate in the House of Lords last month, Baroness Deech said that the UCU was "an unprofessional union". "Universities would do well to cease to recognise it and to deal with alternatives," she said.
She later told Times Higher Education that her remarks related to a motion passed at the UCU's annual congress in May, which asked academics to consider the moral and political implications of their links with Israeli universities.
"These efforts to boycott, or to come as close as possible to a boycott, are contrary to race relations legislation and ultra vires the powers of the union," Lady Deech said. "The UCU has created an atmosphere hostile to Jewish academics and to quality academic research and freedom in this country."
Eve Gerrard, senior lecturer in the Centre for Professional Ethics at Keele University, resigned from the UCU last week. In her resignation letter, she said she could not remain in a union that "sets out to discriminate against its Jewish members".
Lady Deech also accused universities and the UCU of failing to tackle racial tension and extremism on campus.
Sally Hunt, general secretary of the UCU, said: "The UCU has endorsed, and contributed to, the Universities UK guidance to the sector on good relations on campus, which sets out broad policy on racism, including anti-Semitism. The union also works closely with the Department for Innovation, Universities and Skills, individual institutions and other key partners on anti-Semitism and race-related issues. Anyone who values the importance of good relations across the sector would surely understand the need for all parties to work together on such important issues, something the UCU is committed to doing."
In the Lords debate on 26 June, Lord Janner, a former president of the Board of Deputies of British Jews, raised concerns about anti-Semitism on campus. He said: "The Community Security Trust recorded 59 anti-Semitic incidents in 2007, in which all the victims were Jewish students."
In Nottingham, swastikas and anti-Semitic graffiti were scratched on the doors of Jewish students' rooms and in Birmingham, "I hate Jews" was written on the frost on cars, he said.
Lord Janner also said the Government was considering funding a UK-Israel academic collaboration fund. "(This) would be extremely welcome, especially because it offers the opposite to boycotts - stronger, not weaker, academic ties between the two countries," he said.