Smoking in cars where children are passengers should be banned, according to MPs.
Calls to back the Labour-supported amendment to the Children and Families Bill have been supported by the majority in a parliamentary vote.
The vote means that Health Secretary Jeremy Hunt has the power to bring in a ban in England.
Meanwhile, Welsh Government ministers will have to decide whether the same should apply in Wales.
The amendment - passed by 376 votes to 107 - does not compel ministers to make it a criminal offence for drivers to fail to prevent smoking in their privately owned vehicles when children are present.