A convoy led by Kent hauliers is heading to Downing Street this afternoon to hand a petition demanding a 25p-a-litre rebate on fuel duty to Gordon Brown.

Around 80 lorries left the Farthing Corner service station on the M2 at Gillingham, accompanied by a police escort at around 7.30am.

Organisers hoped to be joined by at least another 1,000 hauliers in central London to make it the largest fuel demonstration the capital has ever seen.

Diesel prices have increased by around a third compared with this time last year - it now costs more than £1.20-per-litre - which UK lorry drivers claim makes them uncompetitive when compared to continental Europe.

Protest organiser Peter Knight, of les Knight Transport at Oare, said: "We have a serious problem within the industry.

"We knew the Government wouldn't respond to our last demonstration back in April. They thought we were going to go away, but we're not going anywhere.

"People are losing their businesses, it's just not right . We need action now. Ignore us at your peril."

The Freight Transport Association is supporting the action.

Chief economist Simon Chapman said: "The protests are entirely understandable. Hauliers are at their wits' end. They are seeing their costs rising day by day, week by week."

The FTA estimates that fuel will rise by another 4p per litre in the coming weeks as the most recent rises in world oil prices filter through into the selling price.