Alastair Darling is now expected to defer the proposed 2p-a-litre rise in fuel duty

Drivers filling up on motorway services have been paying as much as £1.11 a litre – or £5 a gallon for petrol.

Chancellor Alastair Darling is now expected to defer the proposed 2p-a-litre rise in fuel duty until later this year in this afternoon’s budget.

The AA said prices at Cherwell Valley services on the M40 were yesterday recorded at 110.9p for a litre of unleaded, above the 110p threshold for a £5 gallon.

The average price of unleaded petrol in the UK is 106.2p a litre, with diesel 112.7p - compared to 89.02p and 92.29p respectively for the same period a year earlier, the latest figures from the AA showed.

Motorists can expect more pain after oil prices in New York reached a record high of more than 109 US dollars a barrel earlier today.

With petrol 17.18p a litre more expensive than a year ago, it is now costing an extra £8.59 to fill up a typical 50-litre fuel tank. The AA added that the monthly cost of petrol was £18.41 higher than the same period last year.

Mr Darling – delivering his first ever Budget speech today – 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.

We’ll be reporting on the Budget as it happens, with comment and analysis on how it will affect you.

What do you think about the Budget 2008? Have your say on the Auto Trader Blog.