Hauliers drove into the centre of London on Wednesday to lobby parliament over the cost of fuel and to plead for a cut in diesel duties.

Trucks from across Britain were escorted by police convoy into Westminster in the third lorry fuel protest this year.

The drivers want Chancellor Alistair Darling to abandon plans to raise fuel duty by 2 pence a litre from October.

They say rising oil prices are threatening to put many hauliers out of business and are seeking a 25 pence per litre cut in the cost of diesel.

"That's what we need to be competitive with our foreign counterparts which are just pouring into our country," Peter Knight, head of haulier protest group Transaction 2007, told BBC television.

The larger Road Haulage Association (RHA), representing 10,000 member firms, says British trucking companies cannot compete against rivals from continental Europe where fuel duties are lower.

It calculates that diesel costs haulage firms 25 pence a litre less in France, 21 pence less in Germany, and 32 pence less in Belgium.

"The government is playing its part in helping to price the road transport industry in the UK off the roads and encouraging foreign commercial vehicles to come in and take our jobs," RHA Chief Executive Roger King told Sky News.

"We are not putting up with that."

The RHA says operating costs have risen by 20 percent for many hauliers and that not all are able to pass this extra cost onto customers.

A Treasury spokeswoman said the government was very aware that businesses were feeling pressure from high fuel prices.

"The Chancellor postponed the planned increase in fuel duty in April because of concern about high fuel prices, and has said he is willing to postpone it again in October if he judges it to be right," she said.