This group of people were identified in a new study carried out by in-car technology group Toad, which found that half of all drivers with hand-held mobile phones will leave them switched on in a car.
Since December 1, using a hand-held mobile phone while on the move has been illegal.
Toad found that the age group most likely to answer their mobile on the move is 35 to 44-year-olds. Drivers in full-time employment are also more likely to break the new law with only 39% of this group always switching their phones off when driving and with no plans to change their habits, the research found.
A total of 58% will answer it if it rings, 12% will happily make a call and 11% will send or read text messages.
Toad said its survey concentrated on the large group of drivers who do not have their mobiles fitted into a fixed cradle in the vehicle.
It found that men in particular are more likely to leave their hand-held mobiles switched on while driving, 55% as opposed to 46% of women, and 46% answer it if it rings against 31% of women.
Identifying middle-aged men as some of the worst offenders, it also found that men are twice as likely as women to make or receive text messages on the move, 9% compared with 4%, and 11% of men will readily make a call, compared with just 2% of women.
Toad Group managing director Nick Grimond said: 'Although it is only weeks since the new law was introduced the results of our survey do give cause for concern.
Whether it is down to attitude or awareness, we clearly have a long way to go before drivers get the message. Too many drivers are risking their lives by driving one-handed with their eyes off the road.
'There is a massive choice of hands-free kits for the driver, so there really is no excuse. The message should be clear – get a hands-free kit or switch it off.'
Last week, Fleet NewsNet warned that the ban was causing a safety crisis on Britain's roads as motorists, including fleet drivers, put their lives in danger attempting to stop and answer calls in unsuitable places.