Dr Peter Maguire (left) handed in thousands of letters

Northern Ireland could be the pilot area for a smoking ban in workplaces across the UK.

It is believed discussions have already taken place between ministers at Stormont and officials of the Department of Health in London.

Smoking is to be banned in all Northern Ireland government departments from January 2005.

The move was announced as a County Down consultant led a delegation of doctors to Downing Street calling for a UK-wide ban on smoking in workplaces.

The ban on smoking in Northern Ireland government buildings, announced on Monday, will see smoking facilities removed and staff forbidden to light up on site. Prisons will be exempt from the ban.

Finance Minister Ian Pearson said: "All government departments and the Northern Ireland Office place considerable importance on creating and maintaining a healthy and safe working environment for all staff.

"The decision to move to a complete ban on smoking from January 2005, has taken into account mounting medical evidence on the risks associated with environmental tobacco smoke in the workplace and the dangers of passive smoking."

The Civil Service in Northern Ireland has had a formal policy on smoking in the workplace since 1987.

The government is considering a public smoking ban

This was revised in 1994, when the decision was taken that smoking would no longer be permitted in premises occupied by staff, except in designated smoking rooms or areas.

Health Minister Angela Smith welcomed the move to a complete ban on smoking.

"This is a very important employer-driven initiative, which is in line with the Tobacco Action Plan, published in June 2003, and will, hopefully, encourage other employers in Northern Ireland to follow. It may also help those smokers who wish to quit."

Meanwhile, letters from 4,500 doctors calling for a ban on smoking in workplaces have been delivered to Downing Street, inside a giant cigarette packet, by representatives of the British Medical Association.

Doctors have got to realise they cannot decide people's lifestyles Forest campaign spokesman Passive smoke risk 'even greater' Q&A: Passive smoking

Dr Peter Maguire, who works at Daisy Hill Hospital in Newry, led the delegation of doctors.

He said: "It is unequivocally clear that 1,000 people die per year in the UK as a direct result of passive smoking. This is unacceptable in the 21st century.

"All workers must be protected from the killing effects of tobacco smoke."

He said three-quarters of the population were non-smokers and of the quarter that did smoke, many wanted to give up.

Dr Maguire, deputy chairman of the BMA's science board, told Radio 4's Today programme the ban introduced in the Republic of Ireland had been successful.

He said 97% of bars were free from smoke within a months of its introduction, compared to 1% of bars in the UK.

But a spokesman for smokers' campaign group Forest said it was not up to doctors to tell people how to live their lives.

Tim Lord, of the Tobacco Manufacturers' Association, told the Today programme the link between passive smoking and serious illnesses was still unclear.

He said the tobacco industry was in favour of more smoke free areas within bars and restaurants and more smoke free venues but wanted this to be done on a voluntary basis rather than by a national ban.

The Ulster Cancer Foundation urged the NIO to introduce legislation and use Northern Ireland as a pilot for a UK-wide ban.

"Since the successful implementation of the ban in the Republic (of Ireland) there has been a growing groundswell of public support for the introduction of legislation here," said a charity spokesman.