The president of the National Union of Students has said she is unable to act to control student unions whose debates on the legitimacy of Israel and Israel boycotts have led to Jewish students feeling intimidated on campus.

Toni Pearce said that because student unions were independent bodies, the NUS could not "police them and cannot impose sanctions even if we are unhappy with what they are doing".

However she acknowledged that the NUS had a responsibility to tackle rising antisemitism on campus.

She said: "Instances of antisemitism on campus have increased. The first step is to recognise it as a problem. People need to be educated in how to recognise it.

"What we can do is train people on antisemitism and particularly in relation to the Holocaust.

"We have a huge task ahead of us but it cannot just be left up to UJS and JSocs. It is one I take very seriously. NUS has a responsibility."

Ms Pearce, who steps down as president in the summer, was speaking after visiting Auschwitz in a tour led by the Union of Jewish Students.

A small group of student-union and NUS representatives spent two days in Poland learning about the pre-war Jewish community and visiting the Nazi death camp.

Ms Pearce said that one of the reasons she had taken part was because she was concerned by rising antisemitism on campus.

"Visting Auschwitz was overwhelming. I think it was quite humbling.

"It has given me an opportunity to be confronted with the most awful aspects of humanity and I think it is important that we face up to those things."