By Nick Triggle, BBC Health correspondent
Under the plan, the age of sale would rise from 18 every year so a child aged 14 today would never be allowed to buy tobacco. Photo: RNZ / Rebekah Parsons-King
The age at which people can buy cigarettes and tobacco in England should rise by one year every year so that eventually no-one can buy them, says UK Prime Minister Rishi Sunak.
MPs were to be given a free vote in parliament on the issue, Sunak said.
Under the plan, the age of sale would rise from 18 every year so a child aged 14 today would never be allowed to buy tobacco.
The idea was put forward by a government-commissioned review in 2022.
Speaking at the Conservative party conference, Sunak said he believed it was the right step to tackle the leading cause of preventable ill-health.
Smoking increases the risk of strokes, heart disease, dementia and stillbirth as well as causing one in four deaths from cancer.
"There is no safe level of smoking," he said.
Smoking rates have been falling since the 1970s. But there are still more than 5 million smokers in England and 6 million across the UK.
Currently, one in nine 18 to 24 year olds smokes, according to the Office for National Statistics.
Sunak told the conference: "If we want to do the right thing for our kids, we must try and stop teenagers taking up cigarettes in the first place.
"Because without a significant change, thousands of children will start smoking in the coming years and have their lives cut short." he said.
"Four in five smokers have started by the time they're 20. Later, the vast majority try to quit, but many fail because they're addicted."
The idea of gradually increasing the smoking age was put forward last year by Javed Khan, the former Barnardo's chief executive, who was asked by ministers to consider new approaches to tackling smoking.
At the time, the government, which was led by Boris Johnson, said such a move was unlikely.
But Sunak has decided to throw his backing behind it as a way of meeting the government's ambition for England to be smokefree by 2030 - defined as less than 5 percent of the population smoking.
On the vote in parliament, he said there would be no government whip demanding which way Tory MPs should vote.
"It is a matter of conscience and I want you all and the country to know where mine is," the prime minister said.
The proposal on raising the age of sale of cigarettes is similar to laws being introduced in New Zealand, where buying tobacco products will remain banned for anyone born after 2009.
Sunak also said the government would consider restricting the sale of disposable vapes and look at flavourings and packaging of the devices, to tackle the rising rates of children using them.
One option could be a ban on the sale of them completely.
Smokers' lobby group Forest director Simon Clark said it amounted to "creeping prohibition".
"It won't stop anyone smoking. Anyone who wants to smoke will buy tobacco abroad or from illicit sources."
But Cancer Research UK chief executive Michelle Mitchell said the announcement on the smoking age was a "critical step".
"If implemented, the prime minister will deserve great credit for putting the health of UK citizens ahead of the interests of the tobacco lobby."
Campaign group Action on Smoking and Health spokesperson Deborah Arnott said what had been announced was an "unprecedented" set of measures which would hasten the day smoking is obsolete.
- This story was first published by theBBC