The two authorities in Caerphilly County Borough charged with enforcing a new smoking ban in cars carrying children are split on how they will approach it.
From October 1, it is illegal for anyone to light up if there is a person under 18 in the same vehicle.
The new law, which is also coming into force in England, means that a private vehicle must be smoke-free if it is enclosed, there is more than one person present and one of them is under the age of 18.
It is also an offence for a driver to ignore someone else smoking when there is an under 18.
The fixed fine for both offences is £50.
Police and local authorities will enforce the regulations, but in Caerphilly County Borough the council and Gwent Police will tackle it different ways initially.
Gwent Police has confirmed it will be following the advice of the National Police Chiefs Council, which has recommended a three-month ‘grace period’.
A spokeswoman said: “Police forces will be taking an educational, advisory and non-confrontational approach when enforcing the new legislation.
“This would see people being given warnings rather than being issued with fines, which would give time for public awareness of the offences to build.”
However, a spokeswoman for Caerphilly County Borough Council has said there will be no such approach from the local authority.
Concerns have already been raised on how the ban will be enforced, with a recent RAC survey suggesting that just one in ten drivers thinking that it will.
RAC spokesman Simon Williams said: “While the motoring public know this new law is coming, our data shows that a significant proportion are not aware just how soon it takes effect.
“It is worrying that nine in ten motorists have concerns about the extent to which the new law is likely to be enforced.
“This is perhaps well-founded as traffic police officer numbers have fallen by nearly a quarter between 2010 and 2014 across forces in England and Wales, so it is hard to see how people flouting the law are going to be caught.
“The new ban joins a raft of other laws that have been introduced in recent years such as making it illegal to undertake or hog the middle lane of a motorway. But without sufficient enforcement there is a real danger that these laws will quickly be forgotten by a large proportion of the motoring population.”
The rules do not apply to e-cigarettes and the law does not apply when someone under the age of 18 is smoking and is the only person in the vehicle.
Health and Social Services Minister for Wales, Mark Drakeford, said: “This change in the law is about protecting those children and young people who have no choice but to inhale the second-hand smoke of others. When people decide to light-up while children are in the car with them they risk the lives of those young people.
“Second-hand tobacco smoke is linked to a range of potentially fatal conditions, including the likes of sudden infant death syndrome, lung infections and asthma.
“Even when the windows are open children cannot escape the dangers of second-hand tobacco smoke – the evidence shows the level of toxic fumes remains high in the enclosed space of the car.”