The BBC has hit back at claims from a former Downing Street spin doctor that the corporation receives preferential treatment.

Writing in the Spectator Tim Allan, formerly deputy to Alastair Campbell and now an advisor to BSkyB, complains that, because many Whitehall figures within the department of culture, media and sport are former employees of the corporation, decisions regarding its funding usually go in its favour.

He specifically points to media advisors in Number 10 and the department for culture media and sport, many of whom worked for the BBC.

"Of course, I am sure that all these advisors leave their employment history at the door as they assess the BBC's proposals, but it hardly gives encouragement to the commercial sector to see such similarity in their employment histories," he writes.

"And if the Corporation's influence at the heart of government doesn't do the trick, it will have to rely on schmoozing MPs. Fortunately, we licence-fee payers fund an extremely large lobbying department for just this purpose, and the Beeb's chief lobbyist is the only one in Westminster allowed an all-access area pass."

However, in a statement, the BBC said it was "plain silly" to suggest it had so much influence.

"Tim Allan is acting as his masters voice, which is what he gets paid to do. It is clearly the case that people move from the media into and out of government, and that the government has recruited people who have worked for the BBC," the corporation said.

"We are flattered that they clearly rate BBC ex-employees. But it is plain silly to say that government can't and won't make up its own mind about what to do on important matters of broadcasting policy.

"People in glass houses shouldn't throw stones. The only two recent cases of people moving from government to the media are Tim Allan from Downing Street to BSkyB and John Newbigin from DCMS to Channel 4. You judge which is more likely to cause concern."

Shadow culture secretary Tim Yeo, however, said that Allan raised "disturbing questions" about government advisors on the BBC.

"Before authorizing more spending on channels which only a few license fee payers can see Tessa Jowell must make clear whether she believes all current BBC programmes represent real public service broadcasting. As for Mr Allan, the question is whether he gave similar advice to Tony Blair before he joined the commercial television payroll. His article shows how important the forthcoming debate about the BBC charter will be," he said.

"It also makes it essential that the government should accept next month, Conservative amendments to the Ofcom Bill to bring the BBC fully under Ofcom and in line with other broadcasters."

Liberal democrat culture spokesman Nick Harvey defended the corporation.

"It is perfectly in order for a publicly funded, public service broadcaster such as the BBC to set the standard for the commercial sector to compete with. But the BBC cannot get every detail exactly, right, and nor should we expect it to," he said.

"We do not want the BBC to be a ghetto for highbrow viewers and listeners. It needs a mixed diet of programming which reflects contemporary society, and if this includes programmes that some people will look down their noses at then this is just intellectual snobbery."