Mr Darling is expected to increase the first-year road tax bill for the highest-polluting cars in a bid to deliver a green budget

Drivers of the most polluting new cars are expected to be faced with a first-year £1,000 road tax bill in tomorrow’s Budget 2008 announcement.

And the Budget 2008 is expected to hit motorists at the pumps too – fuel prices look set to rise by 2p a litre.

But Chancellor of the Exchequer Alastair Darling is likely to delay the 2p rise in fuel prices – announced in 2007 – until later in the year.

Mr Darling – delivering his first ever Budget speech – looks set to introduce a number of controversial measures which will affect drivers of vehicles emitting the most CO2 and reward motorists who own cars with lower emissions.

Cars which currently fall into Tax-band G – such as the Range Rover 3.6-litre TDV8, Citroen C6 3-litre V6, Renault Grand Espace 3-litre dCi and the Porsche Cayenne S – emit over 225g/km of carbon dioxide and currently pay £300 a year in road tax.

Mr Darling is expected to increase the first-year road tax bill for the highest-polluting cars in a bid to deliver a ‘green budget’ to combat climate change.

He will take a number of radical recommendations for cutting carbon emissions from a report penned by Aston University’s vice-chancellor, Professor Julia King.

Her proposals include banning high-emitting cars from town centres and restricting parking to vehicles producing the least pollution.

And London Mayor Ken Livingstone has unveiled his plans for a cleaner capital – hybrid-powered buses.

Mr Livingstone announced his plans for the modernisation of London’s transport network, which include a central London bike-hire scheme and discount tickets for pensioners and war veterans.