An MP known for campaigning for transparency in other politician's spending habits has been rapped across the knuckles for his own.

Norman Baker, Liberal Democrat MP for Lewes, was criticised for sending out an expenses-funded constituency newsletter which featured an advert about work done by a fellow member of the same political party.

The eight-page document is funded by Incidental Expense Provisions IEPs which, according to Parliamentary regulations, should not be used for party political or campaigning material.

Parliament's Standards and Privileges Committee investigated the matter after a complaint by Tristan Donovan, who lives in Southover High Street, Lewes.

It upheld the complaint, agreed the MP had broken the rules but said it did not intend to take further action.

A report issued as a result said: "We reiterate that the inclusion of material of a party political nature is not permissible in publications funded from Parliamentary allowances."

Mr Donovan said: "Norman Baker is very vocal about people not using public money properly so this seems hypocritical that he is doing it himself "It is obviously a misuse of taxpayers' money and shouldn't be used to promote political allies."

Conservative candidate Jason Sugarman said: "Mr Baker is a great one for campaigning about other people who misuse expenses and it seems he has been caught out doing the same.

"He is the first one to jump up and down when other people break the rules and now it is his turn."

Mr Baker said he accepted the finding of the commissioner but argued that the case was a "marginal one".

He said: "It is very important that the highest standard of probity is maintained so of course I accept the judgement. The inclusion of advertising generally was an attempt to reduce the cost on the British taxpayer.

"If I had charged taxpayers more the trouble wouldn't have arisen. This is a marginal case, which is clearly reflected in what they have concluded.

"Next year I will avoid advertising and charge the taxpayer, which is the implication of what they want me to do."

Mr Baker campaigned for two years for information about MPs' travel expenses to be disclosed because he believed it would make Parliament more accountable. Using the Freedom of Information (FoI) Act, he forced the authorities to release the information which was finally published this February.