By Leanne Porritt, pictured, a recent graduate in English language and literature at the University of Leeds, who spent a week on work placement at the Keighley News

Over recent months thousands of smokers have converged on the already crowded streets of New York. They provide the immediate visible effect of Mayor Michael Bloomberg's ban on smoking in public establishments.

The ashtrays and spiralling blue-grey mists traditionally associated with the social spheres of the leisure industry are now an image of the past. A past supplanted by an influx of pedestrians loitering on street corners or sheltering in shop doorways in order to obtain their nicotine fix.

The initiative forms the latest episode in a series of preventative measures enacted against smokers' liberties in America and the UK.

Here in Britain, restrictions are also on the increase. Recent years have seen many major shopping centres and train networks designated as non-smoking areas, and public facilities like buses and cinemas have long been smoke-free environments. The debate focuses around two antagonistic points of view.

Health associations argue that such steps decrease the risk of passive smoking and encourage smokers to "kick the habit". But campaigners for smokers' rights suggest that there remains a thin line between the forced categorisation of smoking as an anti-social habit and the withdrawal of a citizen's democratic right to choice.

This democratic right, however, is obviously debatable. Associations like the World Health Organisation argue that a chosen non-smoker has an equal right not to inhale potentially toxic fumes.

This idea forms a major ideological facet of mayor Bloomberg's ban. Speaking recently, he suggested: "If you are a bar tender or a waiter or a waitress and you work in an establishment where there's smoking, in an eight hour day it's equivalent to you smoking half a packet of cigarettes."

Although the accuracy of the scientific information in this statement remains slightly dubious, the principle is important for the non-smoking camp's campaign.

Recent research carried out by the International Agency for Research on Cancer (IARC) found a direct link between passive smoking and the development of lung cancer. However, this evidence is hotly contested by campaigners for smokers' rights. Only last month the British Medical Journal published a Californian study which controversially challenged the traditional medical viewpoint. The research demonstrated that non-smokers living with a smoking spouse were at no greater risk of contracting coronary heart disease or lung cancer, regardless of how much or how often the spouse smoked. The study, of course, provoked outrage from Cancer Research and the World Health Organisation.

They accused the two American professors responsible for the evidence of supporting the tobacco industry's propaganda in return for personal financial gain.

Yet the research carried out by the IARC is also not without its flaws. Although the results suggested a link between passive smoking and lung cancer, the evidence did not prove significant, therefore preventing its publication.

New York's ban is designed not simply to reduce non-smokers' exposure to cigarette fumes but to encourage smokers to stop by forcefully designating it as an anti-social habit. It is difficult, therefore, to challenge a movement that ultimately has an individual's best interests at heart.

Nicotine is an addictive drug and as such how free are smokers to make that democratic choice to smoke?

Indeed, radical plans circulating recently in the British media suggested that the Government had come to view smoking, along with obesity, as an illness. Future smokers, it is suggested, will be encouraged to sign an agreement with their GPs outlining advisory measures and guidelines on how to quit in exchange for their treatment.

Regardless of which perspective we adopt, what this controversial plan does ensure is that the complex debate surrounding smoking will gather continued intensity before it is finally and equitably extinguished.