Men achieve more first-class degrees than women at Oxford University because it favours males, it was claimed today.

Last year, 22 per cent of men achieved firsts compared with 17 per cent of women.

A study into the figures said the tutorial and finals examination system discriminated against women because the assessment structure favoured a male's argumentative style.

Jane Mellanby and Maryanne Martin, psychologists at the University, conducted the study, which also showed that between 1994 and 1996, 21.3 per cent of men got firsts and only 13.4 per cent of women.

Their report said "a difference in general ability is unlikely to be the cause" of the gap in results and said it was more likely to be related to the nature of the academic assessment system. This was backed by intelligence tests carried out on 115 male and 117 female students taking a range of courses which revealed no significant ability difference.

But women were more anxious about exams. Men were said to have higher expectations and were prepared to take risks.

In October, Oxford launches a two-year study into teaching and results to find the exact reasons for the gap.

Two years ago, former vice-chancellor Sir Peter North recommended an increase in continuous assessment rather than relying solely on final examinations.

Tory leader William Hague's drinking sessions in Oxford have been revealed just days after he boasted of regularly downing 14 pints. The former Magdalen College student partied regularly when he studied in the city, according to friends.

But he preferred beer to the Oxbridge students' traditional tipple, Pimms, according to his biographer, Jo-Anne Nadler.

She described the politician as a bit of a "misfit" at Magdalen.