Using a handheld mobile phone while driving is to be made illegal.
Police say using a mobile impairs driving
Ministers say the new offence is to take effect from 1 December this year, with offenders fined £30 initially - rising to a maximum £1,000 if their case goes to court.
Those caught breaking the ban would also get three penalty points on their driving licences for each offence.
Under current laws motorists can only be prosecuted for using mobiles if they fail to keep proper control of their vehicle - there is no actual law specifically prohibiting the use of mobiles while driving.
The government announced it was considering the law change last August. Since then it has consulted the public and experts on the proposal - with nearly 90% of responses in favour of a ban.
The planned new law will have to be approved by Parliament and be added to the Road Vehicles (Construction and Use) Regulations.
Roads Safety Minister David Jamieson said: "Driving whilst using a mobile phone is dangerous.
"We are all too familiar with the sight of people driving along while holding and talking on their mobile phones.
"Any driver will be distracted by a phone call or text message.
"It affects the ability to concentrate and anticipate the road ahead, putting the driver and other road users at risk.
"Our decision to introduce this new offence will make the roads safer for us all. Missing a call won't kill you - an accident quite possibly could."
Mr Jamieson said other types of behaviour, such as eating and drinking while driving, could be dangerous and were covered by general careless driving laws.
But mobile phone calls posed particular risks as they could often continue for 10 to 15 minutes, he argued.
Research shows that people using a phone while driving are four times more likely to have an accident, says the government.
It is also warning users of hands-free phones that they still risk prosecution for failing to have proper control of their vehicle or for careless or reckless driving.
Studies by the Transport Research Laboratory have suggested using a hand-held mobile is more dangerous than drink driving.
The practice is illegal in more than 30 countries.
The Royal Society for the Prevention of Accidents (Rospa) welcomed the announcement and warned that thousands of accidents had been caused by people talking on the phone, including 20 deaths.
Hands-free phones were being used in at least two of those tragedies. Rospa warned motorists not to swap to hands-free and called for these to be banned as well.
Kevin Clinton, Rospa's head of road safety, said: "We are delighted to see a
new law, but it will not have the impact we have been hoping for if people
switch to hands-free devices instead.
"It is the telephone conversation that is the main problem. People are drawn into the conversation and ignore what is happening on the
road around them."
Mr Clinton was worried phone companies might use the handheld phone ban to market hands-free products.
But Sumit Biswas, from mobile operator Vodafone UK, said: "Drivers should be aware that, just because it is legal to use a fixed,
hands-free mobile phone in a car, it does not necessarily mean it is safe to do
A survey by the RAC motoring organisation last year suggested most drivers backed a handheld phone driving ban.
Andrew Howard, head of road safety for the AA motoring trust, predicted the law change would see phone driving "plunge drastically".
He told BBC News Online: "It's a bit like the seat belts law - nobody bothered with them until the law came out although they knew it made sense."
Why no eating ban?
Mr Howard thought that the new law would give people the excuse they wanted to stop using their mobiles without worrying about not looking "cool".
Conservative shadow transport secretary Tim Collins welcomed any measures which would genuinely improve road safety.
"But there are a number of anomalies and gaps in this new policy," he said.
Mr Collins asked why, for example, mobile phone use should be banned specifically when eating a sandwich or reading a newspaper, were not.