An attempt to change the law to ban smoking in cars with children in them is being launched today.

Liberal Democrat Jim Hume wants to introduce new legislation that would prevent people from smoking in cars while youngsters are present.

The South of Scotland politician plans to introduce a member's bill at Holyrood and today officially launches the consultation for that.

He argues that outlawing smoking in vehicles with children would help give youngsters the "healthiest start in life" and added: "If this can improve a single child's health, I think it is a step we need to take."

He will be backed by health campaigners from the British Heart Foundation Scotland and the British Lung Foundation Scotland.

Leading figures from the anti-smoking group ASH Scotland and from the charity Children in Scotland will also be present at the launch while Dr Sean Semple from the University of Aberdeen will outline his research on the potential exposure to second-hand smoke children experience while in a car.

Countries such as Australia, Canada and South Africa have already passed laws banning people from smoking when children are present in vehicles.

Mr Hume argued: "Passive smoking is entirely avoidable and a private vehicle is one of the few places a child can still be legally exposed to tobacco smoke.

"I want to change this so that we can better safeguard the rights of children in Scotland and give them the healthiest start in life.

"I'll be making that case to MSPs today when I launch the consultation, but I hope that people and organisations from across Scotland will have their say."

Simon Clark, director of the smokers' group Forest, argued that banning smoking in private cars would be a "major intrusion into people's private lives".

He said: "We don't encourage adults to smoke in cars carrying children but legislation is disproportionate to the problem.

"Most smokers are sensible enough to know that lighting up in a car with children is inconsiderate at best and research suggests that only a tiny minority still do it.

"Education has to be better than yet another law that would be very difficult to enforce."

Mr Clark added: "A ban on smoking in private vehicles would represent a major intrusion into people's private lives. What next, a ban on smoking in the home if children are present?"