Britain will become the first European Union nation to introduce plain packaging on cigarette packets after members of the House of Lords rubber-stamped a new law this evening.
Peers agreed the change without a vote after MPs in the House of Commons overwhelmingly approved the move last week, despite fierce opposition from the tobacco industry.
The law will come into effect in May 2016, a year before similar legislation passed in Ireland last month is fully implemented, and four years after Australia made the change.
Smoking rates have fallen in Australia since then, although tobacco companies have blamed the decline on tax hikes.
Deborah Arnott, chief executive of health charity Action on Smoking and Health (Ash), said the vote was a "decisive moment" in the battle to reduce the impact of smoking.
"Today we should remember the millions of people who have died too young from diseases caused by smoking, and the families and friends they left behind," she said.
"This misery must not be inherited by our children."
Penny Woods, chief executive of the British Lung Foundation, said it was "an immense triumph".
"Today parliamentarians stuck to their guns, despite the desperate efforts of tobacco lobbyists, in the name of the 200,000 children in this country who are every year enticed to take up smoking," she said.
The new packages in Britain will be monochrome with the brand name written in plain type next to warnings about the dangers of smoking, according to the plans.
Darker colours such as olive green are proposed, as they are believed to represent danger.
The tobacco industry and pro-tobacco campaigners have said the new law was a sign of government overreach, with the Tobacco Manufacturer's Association saying there was a "complete lack of evidence that the policy will work".