People who use mobile phones while driving could face up to two years in prison, under new guidelines yesterday from prosecutors.
The measures published by the Crown Prosecution Service could also see motorists in England and Wales who cause death on the roads facing life imprisonment.
Detailed guidance on the harsher measures, which were announced earlier this year, telling prosecutors when to bring manslaughter charges, will be outlined in the policy document.
They mean the very worst cases of death by dangerous driving could instead be prosecuted as manslaughter, which carries a maximum life sentence.
Using a mobile phone, sat-nav or an MP3 player while at the wheel will be treated as dangerous driving instead of careless driving, with the chance of up to two years in prison.
Dangerous driving comes with a two-year maximum prison sentence, whereas careless driving can only be dealt with by a community order or a fine.
Director of Public Prosecutions Ken Macdonald QC said, when the measures were first announced in September: "We accept that in cases where there is clear evidence that danger has been caused by their (mobile phones) use - such as texting while driving - then our policy should spell out that the starting point for charging will be dangerous driving."
Current guidelines say manslaughter is "very rarely appropriate" in road death cases, but the change will mean alternative charges could be brought against one motorist.
For example, someone who has killed on the roads could be charged with manslaughter as well as causing death by dangerous driving, leaving a jury open to return the lower charge if they find manslaughter has not been proved.
Last year's consultation paper said other aspects of bad driving may also need to be treated as dangerous driving and carry a jail term, including tailgating, tuning a car radio, "undertaking", running a red light and applying make-up or lighting a cigarette on the move.
Rob Gifford, executive director of the Parliamentary Advisory Council on Transport Safety, said: "It's not every single driver using a mobile phone while driving who faces jail, it's those few drivers whose behaviour leads them to have a crash when they are using a mobile at the same time.
"What people are being reminded is that driving is a complicated activity and it is better to concentrate on driving than talking."
Sheila Ranger, head of campaigns at the RAC, said: "It's entirely appropriate to have this charge available for the most extreme circumstances."
Alan Gordon, vice chairman of the Police Federation, said the new measures contrast sharply with the lenient punishments received by those who commit violent crimes. "I do not condone anyone driving dangerously and agree that all the factors that contribute to dangerous driving should be taken into consideration," he said.
"But the CPS is suggesting a maximum sentence of two years in prison for driving with mobile phones, yet people who burgle and commit assaults are in the main very often only given community service." n Last month, Immigration Minister and Birmingham Hodge Hill MP Liam Byrne was fined £100 after admitting using his mobile phone while driving.
Sutton Coldfield magistrates also ordered him to pay £35 costs and imposed three points on his licence.
Driving while using a hand-held mobile phone was banned in 2003, through an amendment to the Road Traffic Act's Road Vehicles (Construction and Use) regulations. It was toughened up further in February when the minimum fine was raised from £30 to £60 in addition to three penalty points.