A draft EU regulation has revealed that new European cars could have the freedom to fail toxic particulates emissions limits by 50 per cent.
A £22 filter could help cut pollution from petrol cars, but carmakers have lobbied for loopholes and delays to the implementation of new legislature instead of fitting the devices.
Approximately 600,000 people die prematurely each year from pollution-related diseases, but most EU member states have put their support behind raising the EU's pollution standard by 50 per cent above the legal limit stated in the Euro 6 regulations.
According to reports in The Guardian, European manufacturers want to raise the currently drafted 50 per cent leeway to 300 per cent.
Carmakers claim that uncertainty over how future emissions tests will work makes it difficult for them to hit targets.
Florent Grelier, a clean vehicles engineer at the Transport and Environment campaign group, told The Guardian: "This is a petrolgate scandal in the making.
"Unless the European Commission and governments establish strict test procedures to protect the industry from its own short-sightedness, within a few years we will see continuing high levels of particles killing hundreds of thousands of citizens prematurely."
The European Automobile Manufacturers' Association declined to comment.