Kate Hoey, Labour MP for Vauxhall, says her constituents are 'up in arms' about the charge and she is calling for an open debate on the proposed congestion-charging scheme.
'In my view, congestion charging will do nothing to ease the flow of traffic or help pedestrians or indeed anyone who wants to get around London more easily,' she said.
But Robin Cook, Leader of the House of Commons, warned that the matter was in the hands of Mayor of London Ken Livingstone and the Greater London Assembly.
'I would be loathe to enter into a situation in which we sought to override what is, in the first instance their decision,' he said.
This is the second time in less than a week that the Government has voiced concerns over the scheme, after Ministers confirmed they were looking at making exceptions for health workers from the £5-a-day charge, potentially exempting thousands of essential public sector fleet drivers.
Minister of State for Health John Hutton said: 'The London regional office of the Department of Health has been working closely with Transport for London on developing a reimbursement scheme for a number of visitors and staff providing community-based services, so that they are not disadvantaged in any way.'
The Transport for London consultation on congestion charging, which closed last Friday, proposes exemptions for NHS staff who have to use their cars to carry out their duties. Livingstone will make a decision on whether to give the charging scheme the go-ahead in February.
Business leaders have given cautious backing to the scheme. Jane Calvert-Lee, director of CBI London, said: 'The CBI supports the principle of congestion charging as a means of reducing traffic on London's roads and improving air quality. If the details are right a scheme can be made to work but one must not be introduced before it is ready.'