The future of a popular annual walk and marathon for charity is under threat because of a lack of volunteers.

Thousands of people have taken part in the Rottingdean Windmill Walk over the South Downs in its 20-year history, helping to raise thousands of pounds for charity.

But the 2003 event looks likely to be the last unless volunteers come forward to take over planning future events.

For years the walk has been organised by brothers Bernard, Alan and Paul Clifford.

But they say the event planned for Sunday, July 13, will be their swan song.

They are busy planning to move their car accessory business, Cliffords of Brighton, in New England Street, because of the redevelopment of the Brighton station site.

The brothers say it will be difficult to organise the windmill walk, which takes six months to plan, as well as supervise the move of their business.

Bernard Clifford said: "This will be the last windmill walk we will be organising with our wonderful band of dedicated helpers.

"We like to do things properly and the event has now got so popular it has become more time consuming.

"We start working on it in December each year and then more and more of our time is involved as July approaches. Together with running a demanding business which will have to find new premises, it will be difficult to do both."

The walk was first organised to raise funds for Rottingdean Scout Group's headquarters. This was achieved, with a grand opening in 1992, after raising almost £60,000.

By then the event had become so popular that it continued.

The walk has three distances of eight, 15 and 26 miles, starting and finishing at Longhill School, Rottingdean.

Each year about 1,000 entrants of all ages and abilities tackle the course via Firle, Lewes and Kingston.

To take part this year, send a 9x4in stamped addressed envelope to Bernard Clifford, 23 Gorham Avenue, Rottingdean BN2 7DP, or ring 01273 305000.