Convoys of trucks converged on London on Tuesday in a protest by road hauliers over rocketing fuel prices that they say have pushed up their fuel bill by almost half in the past year.

Haulage firms launched the protest as members of Prime Minister Gordon Brown's Labour Party, fearful after dismal electoral results, called for a rethink of plans for fuel and road tax increases due later this year.

Hauliers say the sharp rise in fuel costs has put many of their businesses at risk and added to inflationary pressures as the rising costs trickle down into the prices of goods in shops.

They are seeking special government subsidies.

Diesel fuel is now around 130 pence a litre - more than double the price in the United States where the average diesel price last week was 449 U.S. cents per gallon.

Britain levies the highest fuel duty in Europe with nearly 65 per cent of the pump price of petrol due to tax.

"It is really bad. It is affecting all of us," Joe Cook, a spokesman for the road hauliers, which organised the London protest, said. "It is going up everyday and we just can't cope."

The protests, which are expected to cause traffic chaos in and around London with road closures and go-slows, stirred memories of fuel demonstrations in 2000 when prices hit one pound a litre.

A similar protest also took place in Wales as heavy trucks headed to Cardiff.

Then as now, the demonstrations started in France and spread to Britain.

The hauliers are calling on the government to give them a fuel rebate as essential users to keep the country moving.

"The fuel duty gap was important in 2001 and is even more pressing now, with the UK awash with foreign trucks using low-taxed diesel. We urgently need to look afresh at this issue," the head of the Road Haulage Association wrote in a letter to the Treasury.

"Feelings are running high. We need the government to recognise publicly the industry's plight and engage in a dialogue leading to action."

Organisers said they expected up to 1,000 trucks to take part in the London protest which will culminate in a petition being handed in to Brown's Downing Street office.