Mr Straw in 1968

During his career at the university, he has clashed with government policies, by campaigning against tuition fees for students.

The 21-year-old says he will remain "staunchly anti-fees" if he is elected.

His pledge follows a recent government proposal to scrap fees.

In his election statement, he vows to streamline the union's council by "kicking out time-wasters", and to monitor regularly student feelings at a "grass roots" level.

William will also look at the idea of creating a central student facility, something the university has never had.

He has previously been JCR president at New College.

Minister's embarrassment

At the age of 17 William was accused of selling 1.92 grams of cannabis resin to a journalist from The Mirror newspaper.

In a statement at the time, Mr Straw, then home secretary, said: "William is now learning the lessons of this episode and he has of course my full support in doing so."

Newspaper reports of Mr Straw's son's alleged action were a severe embarrassment to him, having been a hardliner who opposed legalisation of soft drugs.

After being president at Leeds University Students' Union, from 1967-68, Mr Straw became president of the National Union of Students in 1969.