Opponents to congestion charge expansion in west London have held a protest at Downing Street on Wednesday.
The protesters say they are not against road pricing
The West London Residents' Association handed in a letter to Tony Blair outlining their concerns about the cost and effectiveness of an extension.
They want the extension abandoned in favour of road pricing which would tax cars using busy streets at peak times.
But in August last year London mayor Ken Livingstone said will go ahead with the extension subject to funding.
He will need to raise the estimated £110m set-up costs of the extension.
Almost two thirds of 100,000 people consulted said they did not want the scheme in Kensington and Chelsea.
About 20 protesters met at Westminster Tube at about 1040 GMT and held their protest outside the gates to Downing Street at 1100 GMT.
Gordon Taylor, chairman of the residents association, told BBC News: "We don't oppose congestion charging we are opposed to the expensive zone scheme.
"We are very much in favour of road pricing and that will be the way congestion charging will be enforced in London in the future.
"We want Tony Blair to go to the Greater London Authority and change it so the Mayor is made more accountable."