A council leader is calling for instant “four-figure fines” for company vehicle drivers who leave their engines running while parked.
The Government is currently considering proposals to give local authorities more power to reduce pollution after calls by a number of councils.
At present, local authorities are unable to impose penalties unless drivers ignore an initial warning and remain stationary for at least another minute.
The fine is £20 or £80 depending on which regulations the authority uses to enforce the law.
Westminster City Council leader Nickie Aiken told The Times: “Fines are our last resort but when we establish a pattern of persistent idling we need to be able to send a message.”
Aiken said fines for company vehicles, such as supermarket delivery vans, that were caught idling needed to be “a four-figure sum to be a sufficient deterrent”.
Westminster council last year issued just 20 fines last year, while Camden Council, which also wants to be able to issue instant fines, has warned 400 drivers but issued no fines after giving enforcement officers the power to issue fixed penalties in March last year.
Up to 18 local authorities in London have been involved in “idling action events”, with drivers approached and asked to switch off their engines when parked.
Islington council said 80% of drivers switch off if requested in a friendly and non-judgmental manner.
Environment secretary Michael Gove has supported the call to give council officers the power to fine drivers without warning.and told The Times that instant fines for repeat offenders should be considered as a solution to the problem.
He added it was important to ensure the new powers would be used proportionately by councils.
A Department for Transport spokesman said: “We are determined to reduce the damaging environmental impacts of drivers who keep their engines running while stationary, especially those in school zones.
“This is why we are making guidance for local authorities clearer, so that they know how and when to target drivers falling foul of the law. We will also be polling local authorities to understand how any potential review of these powers may look in future.”
Paul Loughlin, a motoring law solicitor at Stephensons Solicitors LLP, added: “These powers are likely to prove an effective deterrent and will go some way to reducing the pollution levels in our towns and cities, however it remains unclear how local authorities will enforce them.
“There is an onus on the Government to spell out how these powers will be used as well as making it clear for drivers to turn off their engines while parked.
“The fines, some of which stretching to £1,000 for repeat offenders, will be keenly felt in particular by businesses and couriers, who often leave their vehicles running while making deliveries.”