Motorists who use mobile phones while driving could face up to two years in prison, under guidelines published today.

Using a mobile phone, sat-nav device or an MP3 player while at the wheel will in future be treated as dangerous driving instead of careless driving, with the possibility of up to two years in jail.

Dangerous driving comes with a two-year maximum prison sentence, whereas careless driving is dealt with by a community order or a fine.

The policy outlined by the Crown Prosecution Service could also see motorists in England and Wales who cause death on the roads facing life imprisonment.

The detailed guidance which was first announced this year will make clear that prosecutors should consider manslaughter charges for the very worst cases of death by dangerous driving.

Sir Ken Macdonald, QC, the Director of Public Prosecutions, said in September when announcing the policy change: “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 that manslaughter is “very rarely appropriate” in road death cases but the change will mean alternative charges could be brought against a motorist.

Someone who has killed on the roads could be charged with manslaughter as well as causing death by dangerous driving, for example, leaving a jury open to return the lower charge if it finds manslaughter has not been proved.

Rob Gifford, the executive director of the Parliamentary Advisory for Transport Safety, told BBC Radio 4’s Today programme: “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, the head of campaigns at the RAC, said: “This is for people who are doing the most outrageous acts on their phone. We still see terrible crashes where people have been texting, driving into the back of stationary queues because they haven’t seen them.

“It’s entirely appropriate to have this charge available for the most extreme circumstances.”