Wales' Labour-led Assembly has proposed a new plan to ban smoking in cars carrying children.
It could result in drivers crossing the border from England being arrested if they have a lighted cigarette in the presence of kids in their cars.
But the proposal has come under fire from motoring groups and MPs.
"I don't condone smoking and everyone knows it is bad for health and can kill people," the Daily Express quoted Tory MP, David Davies, as saying.
"But this move by the Welsh Assembly is reaching the stage where smokers are being victimised which can't be right," he added.
A spokesman for the AA motoring group said: "This sounds like another hare-brained scheme - it would cause confusion and be difficult to enforce.
"It could also cause traffic accidents if heavy smokers were not allowed to smoke and that increased their anxiety and nervousness," the spokesman stated.n the other hand doctors and health groups appreciated the plans.
"We are pleased by this announcement. We know children are particularly susceptible to the damaging health effects of second-hand smoke," said Tanya Buchanan, Wales chief executive of anti-smoking group ASH.
Chris Mulholland, head of the British Lung Foundation in Wales, added: "Smoking in cars harms children and the evidence is piling up that people want to see action to stop it."
The Assembly could introduce legislation within five years.