Lee Chi-fai, chairman of the Hong Kong Dumper Truck Drivers' Association, said that was because those agreeing to pay the surcharge accounted for only 40 per cent of the contractors. He said the rest of the drivers were still losing nearly half of their monthly incomes because of the escalating oil price.

But as more contractors agreed to pay up, Mr Lee said the association would review the situation after one to two days, and would allow drivers who were paid the fuel surcharge to return to work.

'Many of these contractors have received more money from developers or the government due to the increase in fuel costs, but they haven't transferred that extra income to those who are directly affected.'

Contractors of public projects account for nearly 70 per cent of the market. They are willing to pay extra to keep the projects going because if they are delayed, the contractors may have to pay substantial compensation for breaching contracts.

One contractor said the government was particularly concerned about any disruption to the Lion Rock Tunnel Road project.

Horses taking part in the August Olympics may be transported to the equestrian venue in Sha Tin via that route and authorities want to ensure the horses have a smooth trip.

Dump trucks remove debris from construction sites and are crucial to the smooth running of projects.

Contractors of smaller-scale private projects, however, are apparently less enthusiastic about drivers' requests for a surcharge and believe they can always find drivers to do the job at a lower cost.

About 80 per cent of the 2,000 drivers in the trade are self- employed, but the rest are paid staff of transport companies.

'These companies would like to monopolise the market and compete with individual truck owners with cutthroat prices. They are like the illegal discount taxi gangs who try to boost their business at the expense of others,' Mr Lee said.

The Hong Kong Construction Association hoped contractors would negotiate with drivers over the matter but a spokesman said prices were governed by the market economy.

He said the association could not interfere, unlike in the case of last year's bar benders' strike. The case then was about wages, but the current problem involved contracts between businessmen.

The striking drivers plan to use their trucks to block one lane of Wan Po Road - the main artery to the Tseung Kwan O landfill at 9am today.

Much to lose

The bar benders' strike halted 60 projects within one week

This resulted in total daily losses, in HK dollars, of $5m