Rural crews say they are being dragged to the larger coastal towns

They said Brighton in particular gets so many 999 calls ambulances are regularly being pulled from smaller towns to help cope with demand.

Trade Unions have warned more staff are needed and said the problem has been made worse by workers being suspended.

Ambulance workers staged a series of strikes as part of a six-month-long pay dispute with the Sussex Ambulance Trust which was resolved in April.

The Brighton and Hove area tends to get at least 50 emergency calls a day and it is also the place where the vast majority of Sussex's "Category A", life threatening emergencies take place.

'Several people suspended'

The requirement under government guidelines to meet 75% of Category A calls within eight minutes has made it even more common for rural ambulances to be called into the urban areas.

But crews in the north of the county claim while there may be fewer call-outs where they are based, they are more likely to be genuine life or death cases and less likely to revolve around drink or drugs like many in Brighton.

Peter Croxford of the union Unison said: "Crews are having to come in from the rural areas, Crowborough and Uckfield for instance, into the large towns like Brighton, Eastbourne and Hastings.

"Mainly the cover isn't there because we have several people actually suspended and we are having continuing problems with industrial relations with the Sussex Ambulance Trust."

'Peaks do occur'

Ambulance management said people just needed to use the service more sensibly.

David Griffiths, chief executive of Sussex Ambulance Service NHS Trust, said: "In Brighton we do respond to a lot of calls which, whilst they are life threatening, you have to say could in some cases be dealt with in a different way.

"These calls do not arrive equally distributed throughout the 24 hours, so you have peaks.

"When these peaks occur, we have to use - and the public would expect us to use - other resources in order to answer these calls."