Ken Livingstone's congestion charge plan for central London has received mixed reviews from a cross-party committee of MPs.

The Commons transport committee warned on Sunday that the scheme could hit the poor most of all and may push traffic into surrounding areas.

MPs were also concerned that the capital's mayor, Ken Livingstone, had failed to conduct a pilot study before launching what will be one of the biggest and most complicated congestion charging schemes in Europe.

The government also came under fire for failing to engage in a national debate on congestion charging - a problem the committee viewed with "serious concern".

Tony Blair has avoided being drawn on the issue, insisting that powers have been given to local authorities and decisions on how to proceed are down to them.

Reviewing the London scheme, which begins on February 17, the committee said that it could reduce congestion while helping to fund improvements in public transport.

But the report warned that "schemes which merely displace traffic from a city centre to suburban or inter-urban road networks may cure urban congestion at the price of urban decline".

Committee chairman Gwyneth Dunwoody said that the debate had shifted from whether to reduce traffic levels to how to reduce traffic levels.

"Although we support the mayor's objectives, we are concerned about the way the scheme is implemented and the systems which support it.

"It could have a disproportionately negative effect on those with low incomes, on public service workers and on the voluntary sector," she cautioned.

"The mayor has admitted the scheme will cause pain, the money from the scheme must be used to benefit those who will have to rely on public transport."

Dunwoody also predicted that the effectiveness of London's scheme could have a big impact on decisions by other councils to press ahead with schemes of their own.

"The government is willing to offer some support, by allowing local authorities to keep charging revenues to invest in public transport and by making modest sums available to develop schemes.

"But the government has failed to take a lead - if it believes that charging schemes can make a significant impact on congestion, and can deliver real benefits it should come out and say so," said the Labour MP.