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
Toys R Us has scrapped its four collectible dolls based on the characters of the hit TV series Breaking Bad after a campaign by a US mother
Late actress Lynda Bellingham shared how she planned to spend Christmas during a moving final interview on Loose Women to be broadcast later