DON'T raise fuel taxes, we're paying plenty already, is the call to the Chancellor from both the Freight Transport Assoc-iation and the RAC Foundation.

The FTA says that the higher price of oil throughout the world means that Gordon Brown must resist any temptation to increase fuel duty in tomorrow's Budget.

Brent crude has risen by almost 60 per cent in the past 12 months from $33.03 in March 2004 to $52 today. In turn diesel at the forecourt (excluding VAT) has gone from 67.18p/litre last March to 72.14p today, with bulk prices going from 63.18p/litre to 70.15p in the same period.

FTA chief economist Simon Chapman says: "With fuel constituting up to 30 per cent of the operating costs of UK goods vehicles, higher prices have, once again, impacted on already tight margins. The Chancellor is already enjoying higher income from increased oil revenues and VAT and should be satisfied with that.

"Last year's freeze in fuel duty was welcome and should be continued."

The RAC Foundation makes its plea by stressing the plight of rural and other car-dependent motorists. Edmund King, executive director of the foundation, said: "The Chancellor needs to be shrewd as well as prudent this Budget. He should be aware of the voting power of 32 million motorists around the country."

Low-income motorists already spend 24 per cent of their household outgoings on motoring.

King said: "Freezing the level of fuel duty would help the government to regain the confidence of motorists, but will still leave drivers vulnerable to world petrol price rises. Any rise in duty would create further hardship for essential car users.

"Fuel duty is a regressive tax which hits hardest those who can least afford it - the Chancellor should be aware that motorists may vote with their wheels in the forthcoming election if he chooses to penalise them.

"UK motorists already contribute more than £42 billion in motoring taxes of which only £6 billion is invested on our roads. The Chancellor is already benefiting from increased VAT receipts due to the higher cost of fuel."

The RAC Foundation has also condemned moves to downgrade sections of the trunk road network in England and Wales and urged the government to reverse the process which will de-trunk or remove the responsibility for thousands of miles of current trunk roads from the Highways Agency to local authorities.

This is well under way and by March 2006 the strategic network will have been reduced to about 4,165 miles from 6,580 in 2000.

A consultation from the Treasury is looking to downgrade another 50 per cent of roads, such as the M5 west of Bristol, by suggesting they are not roads of strategic national importance.

The RAC Foundation is also calling on the Chancellor to address:

Road investment - Firm plans and targeted expenditure need to be put in place for improvements. Congestion costs the country at least £15 billion a year.

Vehicle excise duty - Bandings should be changed from gradings of AAA to F to a simplified A, B, C, D, E or F to reflect the banding on new fuel efficiency labels.

Motoring taxation - More advance notice should be given on proposed changes so that individuals or fleets buying cars know the longer-term implications.

Insurance premium tax - No increase should be imposed due to high level of uninsured drivers who are already adding £30-£60 a year to the premiums of law-abiding drivers.