Jaguar and Land Rover said they were ahead of the Chancellor’s plans to encourage manufacturers to produce cars with lower carbon emissions.
The two West Midland luxury carmakers – in the process of being sold by current owner Ford to India’s Tata Motors – said they had already cut tailpipe emissions and will have reduced them further by the time new vehicle excise duty bands to impose higher taxes on the most polluting vehicles are introduced in 2010.
They said in a joint statement: "Jaguar and Land Rover are ahead of the Chancellor’s stated intent to encourage automotive manufacturers to introduce technology to reduce CO2 levels.
"Last year we announced a £700 million programme to reduce tailpipe emissions.
"By the time the new VED bands are introduced in 2010, our CO2 levels will have been reduced even further."
Alistair Darling said in his Budget speech Britain’s 30 million road vehicles accounted for 22 per cent of the country’s carbon emissions and more needed to be done to reduce this.
VED is currently based on the size of a vehicle and its emission levels, but Mr Darling said that from 2009/10 there would be six new bands including a top band – band M – for cars emitting more than 255g of carbon dioxide per kilometre.
These cars would pay an increased VED rate of £425.
But cars emitting 150g/k would pay less.
Mr Darling also said from 2010/11, the most-polluting new cars would pay a first-year VED rate of £950, while those with a 130g/k or less emission level would pay nothing.
Land Rover’s concept LRX car, which is widely expected to go into production, would have an emission rating of about 120g/km and so be exempt from VED in the first year.
Christine Oates, tax partner at Ernst & Young, said: "As a Labour chancellor, Mr Darling wants to make the bosses pay for their big company cars. But the automotive industry may be ahead of him: Bentley announced earlier this month that from 2012, all its range of cars will meet a target of 120g/k.
"So if Bentley meets its target, we could have the situation where a company boss in a Bentley is paying the lower tax, while a salesman in a Ford is paying a higher tax. Probably not the outcome Mr Darling would have wished for."
Mr Darling also said he was reforming capital allowances for company cars to increase the incentive to move to lower carbon-emitting vehicles.
"It is right that if people choose to buy a more-polluting car that they should pay more in the first year to reflect the environmental cost," Mr Darling said.
"The changes will provide a real incentive to manufacturers and motorists."
The Treasury estimates that as a result of the reforms, the majority of motorists will be better, or at least no worse, off in 2009.
Industry body the Society of Motor Manufacturers and Traders said a sales tax on higher-emitting cars would have little effect on CO2 emissions despite a clear trend toward cleaner vehicles on the part of buyers.
"Encouraging even more buyers to choose models with class-leading emissions should be the priority," said chief executive Paul Everitt.
"However, introducing what is effectively a sales tax for many new cars is a retrograde step.
"Trying to force people out of high-value cars has no environmental merit and will be seen as a smokescreen for revenue-raising."
The Chancellor temporarily eased the burden on hard-pressed motorists by postponing to October the 2p-a-litre fuel duty rise that had been planned for April "to support the economy and help business and families".
But motorists are already facing a previously-announced 1.84p-a-litre rise in April 2009, and Mr Darling said that there would also be a 0.5p-a-litre rise in real terms from 2010.
While motoring groups welcomed the April 2p postponement, green groups attacked the move.
But the RAC said the postponement was "the only bright spot in a Budget seemingly doing nothing positive for the motorist".
Freight Transport Association spokesman Geoff Dossetter said: "The high price of fuel impacts not just on the transport industry but the whole of UK industry as prices go through the roof.
"In turn, these increased prices must be passed to consumers. For the Chancellor to have addded to this pain by seeking further taxation would have been unthinkable."