UK lawmakers will vote on a landmark bill to gradually phase out smoking

British lawmakers will on Tuesday debate and vote on the government's plans to introduce a landmark smoking ban that aims to stop young people from ever smoking.

The bill, a key policy announced by Conservative Prime Minister Rishi Sunak last year, will make it illegal to sell tobacco products to anyone born after January 1, 2009. It has the support of the opposition Labour Party and is expected to pass. But Sunak faces rebellion from more libertarian-minded members of his party, who criticized the proposals as “unconservative.”

Authorities say that if passed, the bill will create modern Britain's “first smoke-free generation.”

Under the Tobacco and Vapes Bill, children turning 15 this year or younger will never be legally sold tobacco. The legal age of sale that people in England can buy cigarettes will be raised by one year, every year until it is eventually illegal for the whole population.

The bill also includes measures to crack down on youth vaping, such as banning the sale of cheap disposable vapes and limiting their flavors to prevent children from becoming addicted to nicotine.

It is currently illegal for anyone to sell cigarettes or tobacco products and vapes to people under 18 years old throughout the U.K.

Opponents, such as the smokers' rights lobbying group FOREST, said the move will “treat future generations of adults like kids.” Last week former Prime Minister Boris Johnson called the plans “absolutely nuts."

“I think that an outright ban risks being counterproductive, I think it actually risks making smoking cooler, it certainly risks creating a black market,” Conservative lawmaker Simon Clarke told the BBC.

Despite some opposition, the bill is expected to comfortably clear its first hurdle in the House of Commons when lawmakers vote on it later Tuesday.

The plans were believed to have been inspired by similar policies proposed by New Zealand under former Prime Minister Jacinda Ardern, but the country's new coalition government repealed the bill earlier this year.

The government said that smoking won’t be criminalized, and the phased changes mean that anyone who can legally buy cigarettes now won’t be prevented from doing so in the future.

The number of people who smoke in the U.K. has declined by two-thirds since the 1970s, but some 6.4 million people in the country — or about 13% of the population — still smoke, according to official figures.

Authorities say smoking causes some 80,000 deaths a year in the U.K, and remains the number one preventable cause of death, disability and poor health.