Hauliers from across the UK travelled to London for the second time in five weeks to make their feelings about fuel prices known. Drivers parked up on a stretch of the city-bound A40.
The haulage industry says rising fuel prices are pushing drivers out of business. Diesel is now an average of £1.32 a litre, but foreign drivers who fill up on the Continent pay much less.
Hauliers took their protest into the heart of the city. Lorries were escorted by police through Westminster to supportive hoots of the horn from other drivers.
Hauliers want the government to give them a 25p-in-the-pound tax cut on diesel. They say this essential user rebate is vital if the industry is to survive.
Angry protesters waved placards outside the Houses of Parliament. Peter Carroll, from lobby group TransAction 2007, said drivers were having to remortgage their homes because of rising costs.
Some drivers have warned that wildcat strikes could be held on motorways across the country if their demands are not met.