Tobacco giants have lost a legal challenge in London against imposing new rules for standardised packaging due to come into force on Friday, meaning Britain will join a growing list of countries to do so.
Philip Morris International (LSE: 0M8V.L - news) , British American Tobacco, Imperial Tobacco and Japan Tobacco International had challenged the legality of the new regulations, which mean all new cigarette packs sold in Britain will have to be olive green.
Shops will have 12 months to sell existing packets.
"The regulations were lawful when they were promulgated by parliament and they are lawful now in the light of the most up-to-date evidence," judge Nicholas Green said in Thursday's ruling.
Cancer Research UK's chief executive Harpal Kumar said: "This is an important milestone in our efforts to reduce the devastating toll that tobacco exerts on so many families every day.
"It (Other OTC: ITGL - news) 's the beginning of the end for packaging that masks a deadly and addictive product," he said.
The anti-smoking campaign group ASH said the tobacco companies had suffered a "humiliating defeat", adding that the judgement would help other countries looking to introduce similar policies.
Australia, France and Ireland (Other OTC: IRLD - news) have already done so.
The European Court of Justice earlier this month ruled that the Tobacco Product Directive is lawful.
Under the directive, health warnings must cover 65 percent of the front and back of every pack of cigarettes, with additional warnings on the top.
The directive also allowed Britain to go further and introduce its own regulations requiring all tobacco packaging to be the same colour -- olive green -- and with large images designed to act as health warnings.
After the European Court of Justice ruling, a British health ministry spokesman said: "Smoking is the biggest cause of premature mortality and kills over 100,000 people every year in the UK."