Clockwise from left: Patten, Bingham, Toksvig and Neill

The mystery nominee had entered the race just hours before the deadline at 1600 GMT on Tuesday, but their application was checked and failed the vetting procedure.

Four other candidates had been confirmed before Tuesday: the former Governor of Hong Kong, Chris Patten, Lord Bingham of Cornhill, broadcaster and writer Sandi Toksvig and former chairman of the Committee on Standards in Public Life Lord Neill of Bladen QC.

The elections for one of the most prestigious posts in academia will now take place on the 14 and 15 March.

There had been wide speculation that the mystery candidate was former US President Bill Clinton who had been rumoured to be interested in the post.

It is now thought the nomination was little more than a student prank.

'Patten favourite'

An Oxford University spokeswoman said: "All nominations must be checked to see that they fulfil a number of conditions, such as being signed by 50 members of Convocation (all those with Oxford degrees).

"We do not want to go into the individual details of why this nomination was not verified but it is obviously for those sorts of reasons."

With the fifth candidate eliminated, bookmakers William Hill said Mr Patten was favourite at 7/4, with Lord Bingham on 9/4, Lord Neill 11/4 and Ms Toksvig 3/1.

The race for the position of Chancellor began following the death of the previous chancellor, Lord Jenkins of Hillhead, who died in January.