Kate Hoey, MP for Vauxhall, fears key workers will not be able to afford the �5 toll to drive into central London.

Motorists will have to pay the charge from February 2003 under plans put forward by London's mayor Ken Livingstone.

Ms Hoey told the Commons Transport Select Committee on Wednesday the plans will force many key workers to quit their jobs.

'Public transport'

Earlier Ms Hoey told BBC London: "I think it's definitely going to affect all the public services within inner-city areas.

"Many of the people who we attract to work in our inner cities can't afford to live in the area.

"They do travel distances and for some of them it is just not possible to have a suitable journey by public transport."

The select committee also heard from the Mayor of London, Ken Livingstone, and Transport for London which will administer the charge.

Mr Livingstone told MPs that if congestion is not cut by the �5 charge he will consider raising it to �6.