Tobacco firms have been told to remove potentially dangerous chemicals from cigarettes or have their products withdrawn from sale.

The Government has given cigarette manufacturers six months to stop putting harmful additives such as arsenic and ammonia into their products because of the alarming health risks they pose. Some by-products of these chemicals are suspected of posing a cancer risk in addition to the tar from tobacco.

While cigarettes remain strongly associated with both heart disease and lung cancer, the industry is being ordered to create what is, in effect, the least dangerous cigarette so far.

Manufacturers have been given until the end of the year to act. And if they fail, Yvette Cooper, Public Health Minister, will bring in new regulations under the Consumer Protection Act to ban the sale of any cigarettes containing additives on the banned list.

At present manufacturers can legally include chemicals used to make floor cleaner, lighter fuel and mothballs. As well as these ingredients, some brands contain compounds designed to speed up the rush of nicotine and to improve taste. Health campaigners are also concerned that some companies are adding honey, cocoa and vanilla to cigarettes, fearing that this may be an attempt to make them more attractive to children.

Ms Cooper said: "One hundred and twenty thousand people die from smoking each year. The Government is already providing support for smokers who want to give up, but we also want to see the tobacco industry doing more to cut potentially harmful additives and carcinogens from cigarettes."