Conservationists are furious over plans to run a car wash in the forecourt of one of Sussex's most historic buildings.

A sign offering a valet car wash service has been put up at the Grade I-listed Marlborough House in the heart of Brighton.

The building in the Old Steine is considered second only to the Royal Pavilion.

It was built in 1765 and remodelled about 20 years later by the famous architect of the day, Robert Adam, his only work in the resort.

It was named after the Duke of Marlborough, who bought it in 1771.

It passed through a number of owners and for more than a century was used as council offices, including the tourist information office.

In October 1999 it was sold to Eurolink, based in nearby Blenheim House.

Founder of the company Tony Antoniades has said it is a labour of love to restore it to its former glory. Restoration began in early 2003 but some conservationists say it has been too slow.

Now they are outraged over the car wash scheme, even though Mr Antoniades said it was to raise money for the restoration.

He said he was in talks with Brighton and Hove City Council over the plan. He said it would only be short term and would raise money to recreate the Georgian gardens which were originally at the front of the house.

The gardens could cost about £75,000 for the work and research.

Mr Antoniades said similar car washes in Hove and at Brighton Marina raised a lot of money. He said it was a fun way of raising cash and the conservationists should join in and get their cars washed.

The matter is being reported to Brighton and Hove City Council's enforcement team as a possible breach of planning regulations.

Selma Montford, from the Brighton Society, said: "It's an absolute scandal. It's the most important single dwelling house in Brighton and Hove. I'm amazed, shocked and angry."

Brighton and Hove city councillor Averil Older, a former Royal Pavilion guide, said: "I don't think it's appropriate."

A council spokesman said: "We are disappointed to see the forecourt being used as a car wash business. Our planning enforcement team is considering its response."