By Will Smale Business reporter, BBC News

BAT is convinced safer cigarettes will see the light of day

For the world's tobacco companies, the harmless cigarette would be a dream come true.

Instead of facing relentless pressure to quit, smokers would be able to light up happy in the knowledge that their smoke was doing neither themselves - nor those around them - any damage.

The tobacco giants think safe cigarettes would fly off the shelves faster than the most frenzied New Year's sale on the High Street, and their profits would shoot still higher.

Unfortunately for the cigarette-makers, this seems to be little more than a pipe dream.

The hunt for a so-called safer cigarette is a farcical activity Ash spokesman Ian Willmore

Yet despite the disdain of anti-smoking groups - who argue that inhaling any kind of smoke is harmful - the tobacco giants are continuing to quietly spend millions on trying to develop safer cigarettes.

And while a completely safe cigarette may be impossible, the tobacco firms hope that cutting out the toxins in cigarette smoke would at least reduce the health risk substantially.

'Quit or die'

UK firm British American Tobacco (BAT), the world's second largest cigarette-maker, hopes tobacco firms can get cigarettes with reduced toxicants on the market within five to 10 years.

It has 150 scientists working towards that aim at two sites in Southampton and Cambridge.

BAT has 150 scientists working to develop safer cigarettes

At the centre of their hi-tech work, they use cell cultures to grow lung tissue which they then cover with different blends of cigarette smoke to see how the tissue reacts over varying time periods.

"There are between 3,000 and 4,000 different substances in tobacco smoke, with some 100 toxicants," says BAT's harm reduction programme manager David O'Reilly.

"Our aim is to reduce that number."

Yet Mr O'Reilly claims that the search for safer cigarettes is being held back by political pressure and the ongoing demonisation of cigarette firms.

Tobacco smoke contains 3,000 to 4,000 different compounds

Help from the world's top medical research bodies would be appreciated, he says - but he blames pressure from governments and the health lobby for their refusal to offer such assistance.

"The problem we face is that the whole health argument regarding smoking is 'quit or die'," he says - an impractical choice, since cigarettes seem unlikely to disappear any time soon.

"Smokers are either choosing not to give up, or are else not able to quit.

"From our point of view, the public health focus needs to switch from 'quit or die' to reduced risk cigarettes, and the government should encourage universities and the health lobby to work with us on this."

'Idle project'

Unsurprisingly, anti-smoking groups strongly disagree.

"The hunt for a so-called safer cigarette is a farcical activity," says spokesman Ian Willmore from Ash (Action on Smoking and Health).

"Trying to extract the toxins from the smoke is an idle project.