Environmental law firm ClientEarth has launched legal action against the European Commission as it warns that new EU rules on emissions control systems could prompt another diesel scandal.

ClientEarth says the new rules allow carmakers to keep the public in the dark over emissions control systems.

Following the introduction of the new World Harmonised Light Vehicles Test Procedure (WLTP) test cycle for fuel consumption and CO2 emissions figures from September onwards, ClientEarth – which has successfully taken the UK government to court over its failure to tackle air pollution – is challenging new rules that allow car manufacturers to keep their emissions control systems secret from the public.

Under restricted circumstances, car manufacturers are allowed to alter the functioning of the emission control system if it’s necessary to protect the engine against damage.

Although the new rules require car manufacturers to explain what effect any variation to the emission control system has on emissions to national approval authorities, this information remains strictly confidential.

As such, ClientEarth claims this prevents citizens, consumers and NGOs from scrutinising whether any such variation (and derogation) is justified for authentic engine protection purposes or is just because the manufacturer wants to use cheaper components.

ClientEarth CEO James Thornton said: “The Dieselgate scandal showed us we couldn’t rely on these national approval authorities to protect the public and how damaging secretive behaviour by car manufacturers over emissions can be.

“A cosy stitch-up between manufacturers and the authorities will do nothing to reassure the public that the industry has learned its lesson after Dieselgate.”

In response, ClientEarth is calling for the confidentiality provision of Commission Regulation (EU) 2017/1154 to be annulled at the Court of Justice of the European Union, alleging that the Regulation is against EU access to environmental information law and against the international Aarhus Convention, which is designed to ensure transparency and public access to justice in environmental matters.

Thornton added: “Air pollution has been linked to heart and lung disease and can trigger heart and asthma attacks. With people’s health at stake, we cannot allow the car industry to hide behind this smokescreen, we must have transparency.”For more of the latest industry news, click here.