Gordon Brown was warned last night that he faces a new back-bench revolt to rival that over the abolition of the 10p tax rate if he does not backtrack over plans to increase road tax.

Yesterday, Tony McNulty, the Home Office Minister, warned the "vultures" to stop raising questions about the Prime Minister's future "because there is no corpse", but Mr Brown appears to be facing yet another damaging revolt led by Labour colleagues.

Next week, MPs concerned over the planned rise in Vehicle Excise Duty (VED) are due to meet Chancellor Alistair Darling to demand that he shelves plans to slap a retrospective rise on older gas-guzzling cars. Some fear, as with the 10p tax issue, ordinary families could be facing an extra £200 bill.

The Conservatives insist many poorer motorists, who own cars registered after 2001, will be worse off once the VED changes kick in next spring. They claim more than one million motorists will see their road tax double.

The Tory Opposition has described the UK Government's plans as a "ticking timebomb", but Whitehall insists low-income households will not be worse off and that the new green banding of vehicles will encourage the manufacture and use of less polluting cars. However, the UK Government has failed to convince more than 40 back benchers, the vast majority Labour MPs, who are supporting a parliamentary motion tabled by Ronnie Campbell, calling on Mr Darling to reconsider the retrospective element of the planned road-tax rise.

Mr Campbell, who represents Blyth Valley, said: "It's unfair that people bought their cars a few years ago not knowing that the government were going to put this road tax on. When you think that the 10p (tax abolition) was costing people £200 a year; the outbreak of that one was enormous. When people get their road-tax letter through the door next year and find they have an extra £200 to pay, well, I don't have to say any more, do I?"

The Labour back bencher, pointing out how petrol prices were rising steadily, also called on the Chancellor to scrap the planned 2p a litre rise set for October.

Another signatory to the Commons motion, Angus MacNeil, SNP MP for Na h-Eileanan an Iar, said it was clear the increase in VED had not been thought through and that Mr Darling had taken a sledgehammer to the issue. He told The Herald: "It's going to be like the 10p tax: sooner or later they will have to do a U-turn."

Today the spectre of the 2000 fuel protests will be raised when up to 1000 lorry drivers take their vehicles into London to demonstrate against the continuing rise in diesel prices.

A letter will be handed in to No 10 calling on the Prime Minister to introduce an "essential user rebate", reducing duty by as much as 25p a litre, for those commercial operators deemed vital to the UK economy.

One of the protest's organisers, Peter Carroll, who runs a haulage company, claimed that if the Treasury were not to accede to the protesters' demand, then UK haulage firms would go out of business to be replaced by foreign ones, which pay no UK tax.

Joan Ruddock, Westminster's Environment Minister, dismissed any notion that the VED increase had come out of the blue and insisted Mr Brown's government could not afford to abandon its agenda for tackling climate change. "The direction we have all been going in has been clear to people for some time,"she said. "This is the future of the planet."

The Treasury insists the majority of drivers will not be worse off under the VED changes, making clear those cars registered before 2001 will be exempt and that most of those affected will only face an increase of £5 or £10.

The changes, due in April, will mean cars will be put in one of 13 bands from A to M, based on their carbon emissions. Owners of the most polluting cars in band M will pay £440 in tax. Plus from April 2010, people buying the most polluting new cars will pay a one-off "showroom tax" of up to £950.