Rishi Sunak is considering introducing some of the world’s toughest anti-smoking measures that would in effect ban the next generation from ever being able to buy cigarettes, the Guardian has learned.

Whitehall sources said the prime minister was looking at measures similar to those brought in by New Zealand last December. They involved steadily increasing the legal smoking age so tobacco would end up never being sold to anyone born on or after 1 January 2009.