Rishi Sunak has revealed he has never had a cigarette, but said it has “no relevance” to his proposal to raise the legal smoking age annually.

The Conservative Prime Minister defended the announcement against criticism that such a policy would go against “Thatcherite principles”.

Mr Sunak outlined plans in his Tory Party conference speech to introduce a new law that would stop children who turn 14 this year and those younger from ever legally buying cigarettes or tobacco in England.

The move was hailed by health campaigners as a critical step towards creating a smoke-free generation but pro-smoking group Forest said it was “creeping prohibition”.

Asked on LBC on Friday whether he had ever smoked, Mr Sunak, who is also teetotal, said: “No, and it has absolutely no relevance to anything. The issue here is about protecting our kids.

“And the point I was making is, we’ve got an opportunity to do something that will stop our kids growing up smoking.

“Smoking is the single biggest cause we have of death, disability and illness in the UK. It causes one in four cancers. 64,000 people die every year.”

The Prime Minister has said a “free vote” will be put to Parliament on the proposal and it is a “matter of conscience” for MPs.

Labour said the party “will not play politics with public health” and it would “lend” Mr Sunak the support to get the law passed.

Smoking causes around one in five cancer cases and more than one in four cancer deaths each year in the UK.

Almost six million people in England still smoke.