Diesel drivers will be charged an extra 50% to park in a central London area in a bid to cut the air pollution which has blighted the capital.
Westminster City Council is to trial the price hike in parking bays in Hyde Park, Marylebone and Fitzrovia.
Visitors in diesel cars will have to pay £7.35 per hour compared with the standard £4.90 from April 3.
The council said the vehicles were among dirtiest on the roads and therefore hoped the "polluter pays" principle will reduce emissions by driving the cars out.
London mayor Sadiq Khan issued the first "very high" pollution alert for the capital earlier this week, warning the elderly and those with lung and heart issues to avoid strenuous activity.
Air pollution from sources such as factories and cars is linked to the early deaths of around 40,000 people a year in the UK.
It also causes problems such as heart and lung diseases and asthma.
The London Air Quality Network run by King's College, London, said the cold and calm settled conditions last weekend caused a build-up of local emissions from traffic and wood burning and pollution from the continent.
Councillor David Harvey, Westminster's environment cabinet member, said: "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."
Father-of-three Stephen Quinn, who lives and works in Marylebone, welcomed the move.
He said: "The poor air quality in our neighbourhood is palpable.
"We are extremely concerned about the long-term effect that this pollution is having on us, and, more importantly, our children.
"We desperately hope that this pilot will go towards making people realise that things must change."