Six museums in Sussex face losing thousands of pounds in vital revenue and may be forced to close.

Sussex Archaeological Society's stark warning comes after the Government decided to stop some charities taking advantage of the Gift Aid tax concession worth thousands of pounds every year.

The society runs independent museums at Fishbourne Roman Palace near Chichester, Lewes Castle, Anne of Cleves House in Lewes, Michelham Priory near Hailsham, Marlipins in Shoreham and The Priest House at West Hoathly, near East Grinstead.

As part of Gift Aid, they can ask visitors for a donation rather than an entrance fee and can claim 26 per cent of that amount from the Inland Revenue.

The Treasury believes this is not what the scheme was designed for and has announced plans to make it illegal.

But the move has angered museum staff.

Fishbourne Roman Palace has spent £14,000 on new tills to make the Gift Aid process easier.

John Manley, director of Sussex Archaeological Society, said: "Because this was introduced in 2000, to take it away now causes us enormous problems because we have budgeted for this money in the future.

"Already we have cut the post of manager of Lewes Castle and Anne Of Cleves House from a full-time position to a part-time one."

The end of Gift Aid could result in more than just cutbacks.

"Closing is always a possibility," Mr Manley said.

A spokesman for The Treasury said the current set-up was unfair.

He said: "The Gift Aid scheme was to help charities make more of their donations, not to allow museums to stop charging entrance fees."