London drivers caught leaving their engines idling while stationary could face on-the-spot fines under a new anti-pollution campaign.
The campaign, by Westminster City Council, has been launched in an attempt to raise awareness about the environmental and health dangers of vehicle idling.
Alongside these dangers, leaving vehicles running makes for a noisy environment, which can affect nearby residents and businesses.
As part of the movement, from February 4 repeat offenders could face a fixed penalty notice if they don't cut their car engines while they aren't moving.
Council-employed 'air marshals' and more than 50 locals who have been trained to become 'air quality champions' have spoken to hundreds of motorists, encouraging them to switch off their engines when stationary in west London.
Heather Acton, council member for sustainability and parking, told GetWestLondon: "Improving air quality is high on the agenda for Westminster City Council.
"We need to tackle these harmful effects on our health, while also understanding the needs of those who move around central London.
"By speaking to drivers, making them aware of how, by switching their engine off when they are not moving, they can help cut air pollution, we can be more mindful of our impact upon the environment and our health.
These new fines are one of many methods to cut pollution being implemented by Westminster City Council.
From 2018, all newly licensed black cabs will have to be zero-emissions-capable, while new diesel taxis will be banned.
The local authority is also aiming to expand electric infrastructure in the borough, with EV car sharing introduced last year.