A campaign led by medical professionals is calling for all diesel cars to be banned from London.
Doctors Against Diesel claim 9,400 Londoners a year die prematurely from breathing in toxic fumes from diesel engines.
Paris, Madrid, Mexico City and Athens have committed to a ban on diesel vehicles by 2025.
Opponents to the campaign have called the proposals "impractical" and warned a blanket ban could "backfire".
Doctors Against Diesel - comprising doctors, nurses and health professionals - are calling for Sadiq Khan, Mayor of London, to commit to phasing out diesel vehicles from London.
Mr Khan has already said he wants to get rid of diesel buses by 2018.
A spokesman for the mayor said he has no legal powers to ban cars in London and is calling on the government "to face its responsibility and implement a national diesel scrappage scheme now".
"The mayor has more than doubled air quality funding and is doing everything in his power to tackle London's toxic air and rid the city of the most polluting vehicles, but he cannot do this alone" the spokesman added.
According to the campaign, nearly 40% of all nitrogen oxides emissions and PM10 pollution, which is linked to decreased lung function, within London comes from diesel vehicles.
A spokesman for the Society of Motor Manufacturers and Traders (SMMT) said the industry is investing "billions" to reduce emissions and the latest diesel cars are the "cleanest in history".
Figures released by SMMT claim emissions of nitrogen oxides have reduced by 84% since 2000 "thanks to exhaust after-treatments" while new "high tech" filters capture 99% of all soot particles from diesel engines.
The spokesman said: "Diesel makes a vital contribution to our everyday lives fuelling some 99% of the UK's commercial vehicles, which transport essential goods and our emergency services."
'Serious about pollution'
Professor Jonathan Grigg from Doctors Against Diesel told the BBC: "Deaths from paediatric asthma are disproportionately much higher in London than the rest of Europe.
"Air pollution levels in London exceed legal limits and affect people's health at every stage of life.
"If we want to be serious about air pollution we need to be serious about diesel."
But Edmund King, president of the AA, called the proposal "fairly impractical".
He said: "We all want to clean up air quality but you've got to give time, you've got to give incentives.
"Yes get rid of the worst offenders but I think a blanket ban would just backfire."
Transport for London is currently consulting on proposals to improve air quality in the capital.