Graphic images of diseased lungs, stained teeth and drooping cigarette ash mimicking male impotence could appear on cigarette packets after research showed they cut smoking drastically.

The Department of Health is discussing plans to compel tobacco companies to cover a large part of cigarette packs with the disturbing photographs, after trials showed 44 per cent of smokers believed the gruesome images increased their motivation to quit. Research by the Canadian Cancer Society also found that the warnings made 58 per cent of smokers give more serious thought to the health effects of smoking.

An EU directive, which comes into force later this year, will allow cigarette packets with the unsavoury photographs, including bleeding gums and gangrenous limbs.

A spokesman for the Department of Health said the Government was very encouraged by the Canadian findings and was looking at them seriously. "By the end of the year the European Commission will have drawn up rules from members states on how to use images on cigarette packs," he said. "The UK will then have to look closely on what to do. The Canadian research raises the issue of whether a combination of words and pictures could be more effective in encouraging smokers to quit. In particular we would want to watch the ongoing impact of Canadian pictorial warnings to see whether the initial reaction is justified."

The visual warnings were introduced in Canada a year ago and have already played a big part in cutting smoking. The research found that the warnings motivated 27 per cent of people to smoke less inside their home.

Clive Bates, director of the anti-smoking campaign group Action on Smoking and Health, said the visual warnings could save thousands of lives. "The pictures grab you at a gut level and communicate in the same way as advertising," he said. "If ministers are as serious as they say they are about tackling smoking, then Canada has shown that this is a cheap and effective way to get the message across."

The graphic anti-smoking warnings were pushed through the European Parliament by the Liberal Democrat MEP Chris Davies. He has asked to discuss copying the Canadian example with Alan Milburn, the Secretary of State for Health. "The British Government has indicated that it is sympathetic to the idea," he said.

The new rules will also boost the size of health warnings so they cover at least 30 per cent of the front of a cigarette packet and 40 per cent of the back.