A crackdown has begun on parents who park dangerously or leave their engines running during school drop-offs.

Wandsworth Council has announced it will take the action in a bid to improve air quality levels, especially outside schools.

The council said parents on the school run are given a five minute grace period to park on yellow lines while dropping off – and they won’t get a ticket if they are less than five minutes.

But people who park dangerously on top of junctions, across driveways or double parked will face being penalised.

Anyone who parks or stops on the yellow zig-zag markings directly outside school entrances is likely to receive an instant penalty ticket, the council said – handed out either by a uniformed parking attendant or in the post if the offence has been caught on CCTV.

And drivers who stop and leave their engines running unnecessarily are also likely to be fined.

Wandsworth Council’s transport and environment spokesman, councillor Jonathan Cook said: “Most parents on the school run are eminently sensible and do not cause any problems.

“However there are a few that park dangerously or leave their engines running for extended periods of time while talking to their children or other parents or while they do a quick dash through the school gates.

“This is the kind of behaviour we are trying to discourage. Leaving engines running unnecessarily damages the air we all breathe including their own children so we are keen to stamp it out.

“Similarly anyone who stops on the yellow zig-zags obstructs sight lines for both drivers and children crossing the road and can be incredibly dangerous which is why we are concentrating on this too.

“If parents park sensibly, even on a yellow line, they have plenty of time to walk their children through the school gates and return and they won’t get a parking ticket.

“But anyone parking dangerously or leaving their engines running is unlikely to get much sympathy.”