Stormont MLAs have voted to ban smoking in vehicles where children are present.
The measures were proposed by Sinn Fein as amendments to the Health Bill , which is making its way through the Assembly.
Health Minister Simon Hamilton said any such ban would be unlikely to come into effect until early next year.
Despite his opposition, both amendments were passed by oral votes.
SDLP deputy leader and health spokesperson Fearghal McKinney MLA supported the smoking ban.
“All of the evidence shows that children are much more susceptible to illness as a result of second-hand smoke,” he said.
“Kids breathe more rapidly, meaning that they inhale more of the 4,000 chemicals found in cigarette smoke, many of them toxic and at least 50 carcinogenic.
“That means they’re more at risk of developing respiratory tract infections, bronchitis, middle ear disease or sudden infant death syndrome.
“Our amendment to the Health Bill in the Assembly will ban smoking in an enclosed vehicle with children present. This isn’t about telling people how to raise their kids, it’s about protecting our children from preventable illness.
“We’re proposing that the new offence be dealt with by way of a fixed penalty notice.
“The aim of this legislation is to change habits in the same way that the 2007 smoking ban or the ban on using mobile phones in cars has done.”
Speaking after the vote, Sinn Fein MLA Daithi McKay supported the ban.
“Children are particularly vulnerable as they are still developing physically,” he said.
“In evidence to the committee, the BMA highlighted how children breathe more rapidly and absorb more pollutants.
“Children exposed to second-hand smoke in vehicles are at a greater risk of asthma and of taking up smoking in adolescence. We have witnessed high compliance rates for smoke-free legislation. However, its success can be greatly assisted by a public awareness campaign.
“We also need a long term sustained comprehensive tobacco control strategy that looks at all the influences, curtails the tobacco industry, helps people to stop smoking and protects children and others from second-hand smoke.”