BOTH the RAC and the AA are warning that with less than 40 days to go until law changes regarding the use of a mobile phone while driving, up to a third of motorists are confused about the new law or don't even know that it exists.

From December 1, driving while using a handheld phone will be illegal and drivers will be fined a fixed penalty of £30.

The RAC estimates that 33 per cent of motorists could face fines when laws governing the use of mobile phones change, as three million motorists unwittingly break the law.

RAC research also revealed that 16 per cent of motorists questioned intended to invest in an earpiece and wire device not realising that this will also be illegal after December 1 if you need to handle the phone at any point to operate it.

"Our research makes worrying reading and suggests that further explicit guidance is required to ensure that motorists know what they will face when the law changes in December," said RAC spokeswoman Rebecca Bell.

The AA is also warning that between now and December, motorists can still be prosecuted for using a mobile under existing dangerous driving and driving without due care and attention legislation.

Andrew Howard, head of road safety for the AA Motoring Trust, said: "From what I have seen, motorists think they can still get away with using a hand-held mobile when driving. The new legislation is a practical approach to deal with the issue of driving while using a mobile phone.

"We also urge the Government to introduce a hard-hitting campaign to educate motorists."

The RAC and the AA are advising that if you need to use a phone while in your vehicle you should only do so with a fully fitted car kit and keep it simple - try not to get involved in lengthy conversations.