Kwan said: "Being distracted while driving and blocked windscreens could lead to traffic accidents. It poses a danger not only to the drivers themselves, but also to their passengers and other road users."

He believed 90 per cent of cabbies with multiple phones strapped to the dashboard were from "unofficial discount gangs" which accept fares below the meter rate.

Kwan estimates these drivers make up about 30 per cent of the 18,000 licensed taxi drivers.

"Their phones are for business - its their customer hotlines," he said. "But they have to answer phones or read texts, write down bookings and then communicate with their team members while driving.

"We have received a lot of complaints from terrified passengers where taxis were zigzagging across the road while drivers took phone bookings."

Kwan recommended a restriction on phones in a meeting between the Transport Department and taxi unions last month and said he raised the issue amid increasing public concern and a number of traffic accidents involving "discount cabs".

Taxi drivers interviewed by the yesterday welcomed the idea.

Lau Wai-wah said: "Those drivers put the safety of passengers at risk. I think it is unacceptable for taxi drivers to have more than two mobile phones in their vehicle."

Fellow cabbie Tam Tak-ming said: "Those drivers use their phones to take bookings and divert the bookings to other cabbies. I don't think they can be paying adequate attention to the traffic."

He added: "Some of my passengers have told me they don't dare get into those taxis."

A police source said officers would be looking into the problem. "We will collect information on how many taxi drivers do this and how many phones each driver has," the source said.

A spokesman for the Transport and Housing Bureau said it had been looking at how motorists used mobile phones while driving and it would be conducting a review in due time. However, at this stage, there were no plans to amend the ordinances governing the issue, he added.