£50 fine plan for smoking in cars with children on board
People caught smoking in cars with children on board could face a £50 on-the-spot fine in Wales.
A six-week consultation on the ban, which was first announced in July, is being launched on Thursday to protect under-18s from second-hand smoke.
The proposed legislation is set to start in 2015.
The use of e-cigarettes in cars carrying children could also be banned depending on the public response.
First Minister Carwyn Jones said: "Children and young people have the right to breathe clean air and enjoy smoke-free environments.
"Protecting children from exposure to second-hand smoke will help give them the best start in life."
Any new regulations would apply solely to Wales, but the Welsh government has previously said it was in touch with the Department of Health in England to "co-ordinate approaches" on the issue.
Welsh government-backed research by Cardiff University has suggested one in 10 children in Wales continue to be exposed to smoke in family cars.
Chris Mulholland, head of British Lung Foundation Wales said: "We're pleased to see the policy high on the agenda at the start of the new assembly term, and we look forward to the ban coming in to force as soon as possible."
Elen de Lacy, chief executive of Action on Smoking & Health (ASH) Wales, welcomed the consultation.
"Concentrations of smoke inside a car can reach dangerous levels very quickly and exposure to second-hand smoke is a substantial threat to children's health.
"Laws stopping smoking in cars with children are popular with the public and we urge the government to bring them into force without further delay."