In February 2007, the fixed penalty was doubled to £60 and increased to include three penalty points. Cases that reach court can involve discretionary disqualification and a maximum fine of £1,000 - or £2,500 in the case of the driver of a bus, coach or goods vehicle.

While as many as 64% of those polled said they had never used a hand-held mobile while at the wheel, only 3% said they had never seen another motorist doing so; 57% said they had seen someone that day, 18% said the previous day, 18% said the previous week and 4% the previous month.

Asked when they themselves had last used a hand-held mobile while driving, 12% said that day, 5% the previous day, 8% the previous week and 11% the previous month.

The editor of What Car?, Steve Fowler, said: "The message is obviously not getting through - if you use a hand-held mobile phone while driving, you may end up killing yourself or others.

"Research has shown that using a mobile phone at the wheel could be more dangerous than drink-driving. Yet it seems you don't have to travel far to see someone oblivious to the dangers."

Police can stop someone driving badly and seek a reason, if they suspect the driver was using a phone. If it goes to court, phone records can be checked to determine whether a phone was being used. There is an exception for 999 or 112 calls in a genuine emergency where it would be unsafe or impractical to stop.