THOUSANDS of fleet drivers could be exempted from London's proposed congestion charging scheme after essential users in the public sector launched a concerted campaign against the tolls.

Stephen Byers, Minister of State at the Department of Transport, Local Government and the Regions, is under pressure to exercise powers that allow him to override congestion charging schemes and hand out 'free passes' to public servants such as nurses and care workers who use a car as an essential tool.

The Transport for London consultation on congestion charging, which closed on Friday, proposes exemptions for motorcycles, buses and coaches, military vehicles, vehicles used for carrying disabled passengers and emergency service vehicles.

But this does not cover staff vehicles used for private purposes, such as travelling to and from work, or employees from outside the area visiting patients within the charging zone.

Angie Bray, GLA Conservative spokeswoman on transport, has written to all London Labour MPs, saying: 'It is an inescapable fact that for many the car is not a luxury but a necessity. Since there are no major public transport improvements scheduled to be operational prior to the beginning of the scheme in 2003, for many there are no real alternatives.'

'Care workers and public servants such as nurses will be forced to pay more than £1,000 a year in extra taxation just to be able to carry on with their work.'

Bray says 100,000 exemptions would be needed to cover social, emergency and charity workers.

The Westminster Primary Care Group, which represents staff tending to residents in central London, has written to Mayor of London Ken Livingstone expressing 'serious concerns' over the effect of congestion charging.

The letter from chairman Dennis Abadi and vice-chairman Maher Shakarchi, says: 'The majority of health personnel need their cars to visit patients and carry medical equipment and medications.'

The letter warns that congestion charging will add to financial pressure on the NHS if it has to reimburse staff for road charges.