Doctors have called for tougher controls on cigarettes and alcohol, including a ban on smoking while driving.

The British Medical Association (BMA) voted in favour of more restrictions on licensing hours and introducing a minimum price of 50p per unit of alcohol at its conference in Cardiff.

BMA members who back the plans hope the association will persuade the government to pass new tobacco and alcohol laws across the UK.

Those against stricter regulations say they would intrude on 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 and save the NHS money.

Douglas Noble, a London doctor, described smoking in cars as a toxic threat to people's health and called for legislation to ban it completely.

"In-car 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," he said.

"It would be safer to have your exhaust pipe on the inside of your car than smoke cigarettes.

"This would protect non-smokers – particularly pregnant women and children. There is also evidence linking driving and smoking to a higher rate of road traffic accidents."

The effects of cigarettes and alcohol on the nation's health has been a key issue during the BMA's week-long conference in St David's Hall, Cardiff.

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

Dr Sue Robertson, a member of the BMA's Scottish council, said 24-hour drinking in the UK, introduced in 2005, needed to be scaled back.

"Less time selling drinks equals less drinks being sold," she said. "In one day in Scotland alone, alcohol will cost £97.5m in terms of health, violence and crime.

"The annual healthcare costs of alcohol in England alone are £1.7bn to £2.4bn."

Delegates also heard calls for a minimum price on alcohol, and opinions that such a move would stop supermarkets offering the cut-price drinks deals that have put many pubs out of business.

Robertson said a charge of at least 50p a unit would reduce problems such as underage drinking as well as saving the NHS £1.3bn in 10 years.