Westminster City Council has announced it will trial emissions-based parking surcharges for diesel vehicles parking within central London.

From 3 April, owners of diesel vehicles will need to pay an additional 50% on top of the current £4.90 hourly rate when parking in the F Zone area of the borough, which covers Hyde Park, Marylebone and Fitzrovia.

The council said the scheme aims to reduce vehicle emissions, and any money raised from the trial would be put towards initiatives to support the uptake of sustainable transport.

The trial will last for up to 18 months and is subject to regular review, a spokesman said. When drivers pay for parking in the affected areas they have to enter their license plate information, which will then bring up relevant charges automatically.

Westminster City Council said the pilot would provide insight into how the policy works and help it find out whether any positive behavioural changes arise from the scheme, which could then be replicated elsewhere.

“Residents and visitors tell us all the time that air quality is a key concern in central London and we have consulted with our partners and local stakeholders on this practical step in improving our health and wellbeing,” said David Harvey, cabinet member for environment, sports and community. “Additional charges for diesel vehicles will mean people think twice about using highly polluting cars and invest in cleaner transport that will make a real difference in the quality of air we breathe and our environment.”

FairFuel UK described the move by the London borough as “selfish and short-sighted”.

“The decision by Westminster Council to add 50% to the cost of parking diesel vehicles is just greedy unscrupulous money grabbing using dubious emissions evidence as the reason to fleece hard working motorists,” said Howard Cox, founder of the FairFuel UK campaign.

In 2015, the council gave parking wardens the power to speak to drivers and issue £20 fines for leaving engines running, while last year, it deployed two ‘Air Force’ officers on the borough’s streets with the aim of combating pollution and raising awareness of air quality.

At the time, Westminster claimed the “Air Force” scheme would “deliver a marked drop in engine idling, a key source of emissions in London”.