Rishi Sunak has announced plans to eventually ban smoking by raising the legal age people can buy cigarettes by one year, every year.
It would mean someone who is currently 14 years old will never be legally be sold a cigarette.
The prime minister said the change would “save more lives than any other decision we could take”.
Sunak told the Conservative Party conference in Manchester on Wednesday that his MPs would be given a free vote on the new law.
It means Tory MPs will not be ordered to back his plan if they do not want to.
The proposal mirrors the law in New Zealand, where tobacco cannot ever be sold to anybody born on or after January 1, 2009.
Commenting on the government’s announcement, Christopher Snowdon, Head of Lifestyle Economics at the free market think tank, the Institute of Economic Affairs, said: “Not only is this prohibitionist wheeze hideously illiberal and unconservative, it is full of holes. It will create a two tier society in which adults buy cigarettes informally from slightly older adults and will inflate the black market in general.
“It may well breach equalities legislation and will very likely be challenged in the courts. It will certainly create huge problems for retailers and may ultimately require a system of national ID cards.”