The number of smokers attempting to quit dropped by 11% in Scotland in the second year since the smoking ban was introduced.

Ministers admitted the figures released ahead of the second anniversary of the ban today, were disappointing.

They revealed 41,424 people tried to give up with the help of the NHS during 2007, compared to 46,466 the year before.

The trend varied in different parts of the country with NHS Grampian recording a massive 47% fall in the number of people trying to kick the habit.

This is due to "limited services" being in place in the area during the period, according to an official report on the findings, as well as a slump in demand.

Concern is already circulating about the future of NHS smoking cessation services after the Scottish Government announced investment is being frozen at the same level for the next three years.

Dr Richard Simpson, Labour's spokesman on public health, said the real-terms cut in funding would affect some provision.

He added: "The trend of people trying to give up smoking is moving in the wrong direction, with the NHS Grampian figures being the most worrying.

"What is important, is not just the number attempting to quit, but how good the support services are.

"We have really got to focus on this because it is still such a killer. One in four deaths is associated with smoking in Scotland."

The move to ban smoking in enclosed public spaces has been widely applauded.

"A study published last autumn revealed the number of heart attacks treated in nine major Scottish hospitals fell by 17% the year after the law was introduced.

But not all health boards are seeing a decrease in the number of people trying to quit. In fact, half recorded a rise last year, although in some cases this was attributed to better record-keeping.

However, the vast majority of people who attempt to quit are unsuccessful. For Scotland as a whole, the percentage of patients still shunning tobacco three months after giving up last year was 19%.

Shona Robison, Minister for Public Health, said: "While it is disappointing that the number of people trying to quit smoking has fallen since 2006, it is really encouraging that more than 40,000 people tried to give up last year.

"The primary aim of the smoking ban was to reduce exposure to second-hand smoke. It is heartening to see that it is also encouraging people to stop smoking and in turn reduce ill-health caused by smoking."

She added that a five-year action plan for tackling smoking would be published later this year, and would focus on trying to discourage young people from taking-up the habit in the first place.

Sheila Duffy, chief executive of Ash Scotland, said it was inevitable that more people would try to stop smoking in the immediate aftermath of the ban when there was widespread publicity about the health risks. "This shows that there is a need for a continued mass media campaign to let people know that smoking cessation advice and support is available," she said.

"Giving up smoking has immediate and long-term benefits for all smokers at any age and figures indicate that smoking cessation services are saving lives at a cost of around £800 per life-year saved."