The number of drivers using mobile phones behind the wheel has doubled in the last two years, a report by the Transport Research Laboratory has shown.
The shocking new figures come despite a police clampdown and increased penalties, reports News of the World.
According to the report, nearly one million drivers across Britain are believed to regularly break the law.
The findings are based on observations at 33 London locations where 2.8 per cent of car drivers were seen on mobiles - up from 1.4 per cent in 2007.
The report has shown that the proportion of vanmen soared even higher from 1.8 to 4.5 per cent, and for cabbies it leapt from 0.7 to 1.6 per cent.
In February 2007, there was an enforcement blitz when penalty points were increased to three and the fine doubled to 60 pounds. Offenders may also face court charges.
The Royal Society for the Prevention of Accidents described the rise as 'extremely disappointing'.