They're supposed to be among the best and the brightest of Britain's student population, but lately the Oxford University rugby boys can't seem to help making fools of themselves.

Last week it was Bring a Fit Jew night and yesterday we learned that some of the same partygoers had had a whale of a time earlier this year "blacking up" for a Safari Bop.

Apparently, they see this as a jolly good show. One of the rugby boys, Phil Boon, doesn't seem to think he's done anything wrong, telling the Daily Mail: "I have organised a lot of party nights but I do not see why there should be any fall-out.

"And anyway we changed the name of the party from the Fit Jew thing to Bring a Fit Girl to Dinner."

Boon also said: 'Blacking up for the Safari Bop was just going along with that theme. We dress up for a lot of parties. I have not had people telling me that either of the themes were offensive."

Isn't it obvious that the peddling of such racial stereotypes is deeply offensive?

Those individuals who reportedly invited participants in the Bring a Fit Jew Night to dress themselves as Orthodox Jews with pretend sidelocks attached to their heads and carrying bags of money, should be thoroughly ashamed of themselves.

The peddling of anti-Semitic stereotypes is an insult to a community that has suffered throughout history from the use of such imagery to create the myth of "the great Jewish conspiracy".

And - as NUS's black students' officer, Bellavia Ribeiro-Addy has commented – "blacking up' is completely unacceptable, and belongs to an embarrassing and closed chapter of British history.

Maybe Boon has never met anyone who's black. Given that he is a student at Oxford University, it's certainly possible. Last year, just 178 out of more than 10,000 UK applicants to Oxford defined themselves as black.

This is a university which struggles enormously to attract the brightest students from under-represented backgrounds, not least because so many of them feel that they won't fit in.

I don't believe these clowns represent the majority of students at Oxford University, or the wider student population in general. This year, Oxford University Students' Union is led by its first ever black president, Lewis Iwu.

The students' union and the student body work hard to support the university in encouraging applicants from diverse backgrounds to apply to Oxford. But their work - and their progress - will be set back by these incidents.

This small-minded, self-indulgent behaviour has brought Oxford University into disrepute. The university will doubtlessly be privately seething at the damage to its reputation caused by a small number of students.

But the university needs to set an example. If these students don't understand why their behaviour is so offensive and inappropriate, then it's up to the university to teach them a hard lesson.

• Wes Streeting is president of the National Union of Students