Shadow public health minister Luciana Berger has welcomed the result of a vote to ban smoking in cars with children as a "great victory for child health", but warned ministers not to "kick this into into the long grass".
"This is a great victory for child health which will benefit hundreds of thousands of young people across our country. It is a matter of child protection, not adult choice," the MP said.
"A time-limited consultation may be necessary on the practical details of implementation, but we will be watching closely to ensure the Government don't try and kick this into the long grass."
Some MPs have questioned how the plans will be enforced with some criticising the plans as a "nanny state" ban.
A representative from a smokers' group has said the law should not be used to "stigmatise smokers as potentially unfit parents" after MPs approved plans to ban smoking in cars carrying children.
Simon Clark, director of the smokers' group Forest, said he was "disappointed but not surprised" by the result and warned that the Government will ban smoking in the home next:
Legislation will have very little impact because so few adults still smoke in cars carrying children. Those that do will carry on because it will be very difficult to enforce.
The overwhelming majority of adult smokers know how to behave towards children and the law should reflect that.
It shouldn't be used to stigmatise them as potentially unfit parents who can't be trusted to do the right thing without state intervention.
If you believed everything you heard in the House about the threat to children's health it's a miracle anyone who was a child in the fifties and sixties, when a large majority of adults smoked, is still alive.
Government has banned smoking in public places. Now they're going to ban it in a private place. The home will be next.