Smoking cigarettes in a vehicle is more damaging to your health than breathing in exhaust fumes, a British leading doctor has claimed.

British Medical Association public health expert Douglas Noble made the shock claim as his colleagues called for tougher tobacco and alcohol controls.

BMA members voted in favour of a ban on smoking while driving, more restrictions on licensing hours and introducing a minimum price of alcohol.

The union hopes to use its influential position to persuade the UK Government and its counterparts in Wales, Scotland and Northern Ireland to tighten up its licensing legislation.

Those against stricter regulations say it would intrude upon people’s liberty – and labelled a ban on smoking while driving as being “unenforceable”.

But supporters insist the measures, if implemented, would improve the nation’s health.

London-based Dr Noble said: “In cars, particle concentrations are 27 times higher than in a smoker’s home and 20 times higher than in a pub, in the days when you could smoke in public places. “It would be safer to have your exhaust pipe on the inside of your car than smoke cigarettes in terms of fine particular matter released.

“A ban would protect pregnant women and children.”

Cigarettes and alcohol was a key area of debate during the third day of the BMA’s week-long annual conference in St David’s Hall, Cardiff.

As well as backing calls for a blanket ban on smoking in cars, members supported two motions for more restrictions on the sale of alcohol.

BMA Scottish Council member Sue Robertson said: “Less time selling drinks, equals less drinks being sold.”