Smoking in cars with children will be outlawed in England from next October following a final vote of MPs.
The Department of Health (DoH) previously said regulations laid before Parliament to make private vehicles carrying under-18s smoke-free were to ''protect young people from the serious health harms of smoked tobacco''.
A change in the law will come into force on October 1 after 342 MPs voted in favour compared to just 74 against.
Chief Medical Officer Dame Sally Davies said: “The passing of regulations to make smoking in cars carrying under 18s illegal is a significant victory for protecting children's health from second-hand smoke.
“Smoking just a single cigarette in a car exposes children to high levels of air pollutants and cancer-causing chemicals like arsenic, formaldehyde and tar.”
Kevin Fenton, national director for health and well-being for Public Health England, said: “Many parents aren't aware that over 80 per cent of second-hand smoke is invisible and odourless.
“A completely smoke-free home and car is a strong and positive step towards protecting the health of our children.”
Penny Woods, chief executive of the British Lung Foundation, said: “This is a tremendous victory for the half a million children being exposed to second-hand smoke in the family car every week in England. Parliament has spoken and we now look forward to the introduction of a ban on smoking in cars with children by October 2015.
“We urge the government to show the same commitment to introduce standardised packaging for all tobacco products, in order to protect the 200,000 children taking up smoking every year in this country. We are certain that these measures together will prove to be two of the most significant milestones for public health since the smoke-free legislation of 2007.”
The charity previously said it estimated that 430,000 children are exposed to second-hand smoke in their family car every week.
The ban comes as a consultation has been taking place on proposals to ban under-18s from buying electronic cigarettes.
Kay Boycott, chief executive of Asthma UK, said: “The impact of smoking on the health of people with asthma is enormous – it reduces lung function, increases the risk of asthma attacks and can cut down the effectiveness of some asthma medicines.”
She continued: “Parliament has made great progress today but more must be done. We now need to see standardised packaging on all tobacco products become law before the end of this Parliament.”