The chair of the Royal College of Physicians' tobacco advisory group, John Britton, says the RCP is calling on MPs to support "this important health amendment".
The evidence shows the importance of protecting children from passive smoking, and cars are still a major area of exposure.
Such exposure is widely associated with adverse health effects, including an increased risk of respiratory and allergic symptoms. That is why the RCP is calling on MPs to support this important public health amendment.
But pro-smoking groups have said the restriction would be an "unnecessary intrusion into people's private lives.
More top news
Twelve people have been killed and three injured after a pick-up truck and a church minibus crashed head-on in Texas.
Revenge porn offenders who attempt to magnify their targets' humiliation will face the toughest penalties under new sentencing proposals.
A remarkably mild night with misty low cloud on the hills of Scotland, Wales and north-west England and further rain in places.