Media magnate Rupert Murdoch funds a Chair of Language and Communication at the university, a connection which prompted Mr Bennett to refuse to accept the award.

Writing in the London Review of Books, Mr Bennett says "I'm aware of the arguments about bad money being put to good uses, but I still think that Murdoch is not a name with which Oxford should have associated itself."

The funder of the Rupert Murdoch Chair of Language and Communication

In making the decision to reject the offer, Mr Bennett says that he might be "sneered at as showing off", but he writes that it is important to make public the reasons for his refusal.

"Murdoch is a bully and should be stood up to publicy and so, however puny the gesture, it needs to be in the open," Mr Bennett writes.

The turning down of a degree from his former university left the playwright with little evident satisfaction.

Describing his feelings when he replied to the university in November 1998, he says: "I wish I could say that this refusal leaves me with a warm feeling of having done the right thing, but not a bit of it. I end up, as so often when I tried to get it right, feeling I've slightly made a fool of myself."

An Oxford spokeswoman said that the university regretted that Alan Bennett did not want to accept the honorary degree, but respected his decision.

In response to Mr Bennett's criticisms, the university spokeswoman said that the chair had been set up under the same terms as any other externally funded post.

The funding, in the form of an investment which delivers an income, could not impose any constraints on the appointed professor, who would always have "total academic freedom".