As reported by the Financial Times, the changes, which were proposed this week at a meeting in Brussels, would give manufacturers until late 2019 to ensure that new types diesel cars fully comply with real-world nitrogen oxides emissions levels whilst newly made diesel cars based on existing models would have until 2020.

Previously the commission proposed that real-world emissions tests be fully implemented in 2017. However, the new proposals would mean that cars would be allowed to exceed the 80mg per km EU limit on NOx emissions by as much as 60% until September 2019.

The respective deadlines would be pushed back for new diesel cars based on existing models to September 2018 and September 2020.

Last month saw campaign group T&E publish research showing that only one in 10 new diesel cars is compliant with EU air pollution limits, just days after the Euro6 auto emissions standard was introduced.

It added that on average new EU diesel cars produce emissions about five times higher than the allowed limit whilst the worst car was found to emit 22 times the limit.