Banning smoking in public places also leads to cuts in the amount people smoke at home, research suggests.

People are likely to implement their own "home bans" on lighting up once new laws come into force.

Writing online in the journal Tobacco Control, researchers carried out surveys between 2003-4 and 2008-9 depending on when bans took effect.

The polls involved 4,634 smokers in Ireland, France, Germany and the Netherlands.

Before a ban came into force, most smokers had at least partial restrictions on smoking at home, with young children and support for a smoking ban important factors.

However after new laws came into force, there was a rise in all countries in the proportion of people banning smoking at home - rising 25% in Ireland, 17% in France, 38% in Germany and 28% in the Netherlands.

Home smoking bans were more likely to be imposed when the smoker planned to give up, when there was a birth of a child, and among those smokers who supported a smoking ban in bars.

"Opponents of workplace or public smoking bans have argued that smoke-free policies - albeit intended to protect non-smokers from tobacco smoke - could lead to displacement of smoking into the home and hence even increase the second-hand smoke exposure of non-smoking family members and, most importantly, children," the experts said.

In fact, banning smoking in public places "may stimulate smokers to establish total smoking bans in their homes".