Smokers in deprived parts of one of Scotland's biggest cities are being offered food vouchers worth 50 pounds a month if they give up smoking, the National Health Service said on Saturday.

They will have to pass weekly carbon monoxide breath tests at their local chemist to prove that they have kicked the habit, NHS Tayside said.

During the three month trial, they will receive money credited to a card that can be used to buy groceries. However, they won't be able to use it to buy cigarettes or alcohol.

Paul Ballard, deputy director of public health with NHS Tayside, said he hoped the cash incentive would help persuade more people to try to stop smoking.

"After Glasgow, Dundee probably has proportionately the biggest smoking problem in Scotland," he told the Scotsman. "It is going to cost around 1,200 pounds per person, but when you compare that to the cost of treating them for smoking-related diseases, then it is a drop in the ocean."

A similar scheme arranged for pregnant women in the area last year was a success, he added.

Sandy Watson, chairman of the NHS Tayside health board, said the idea was an innovative one that could be extended to other parts of Scotland if it helps people to quit. About 1,000 people are expected to take part.

Smoking in all enclosed public places was banned in Scotland in 2006 in an attempt to improve people's health.

Life expectancy in Dundee is among the lowest in Britain, according to Scottish government figures. It is also the third most deprived area in Scotland.

Health workers in Scotland's fourth-biggest city have been trying to promote healthier eating, exercise and quitting smoking.