The group ranked the top 13 carmakers in Europe by sales, by assessing their performance against the European Union’s CO2 emission targets for 2021, and found that Volkswagen, BMW, Daimler and Jaguar Land Rover are struggling to achieve their individual requirements, despite making reductions in emissions of 17-22%.

It added that overseas carmakers such as Hyundai, Nissan, Ford and GM are close to their specific 2021 targets but may find it difficult to make the final reductions they need to hit the exact number.

PA Consulting also said that the top performers on track to meet their individual requirements are Renault, Peugeot Citroen, Fiat, Toyota and Volvo. Carmakers are required to ensure that their new car fleet does not emit more than an average of 130 grams of CO2 per kilometre by 2015 and 95 grams by 2020-21.

However, Thomas Goettle, automotive expert at PA Consulting Group, said: “Our analysis shows that all car makers need to maintain a real focus on meeting their targets. They should be looking to reduce vehicle weights, developing more efficient or alternative powertrains and engines, as well as securing a bigger share of smaller, hybrid and electric vehicles in their fleet.”

Goettle added: “It could be possible that the World Harmonised Light Vehicles Test Procedure (WLTP) test cycle, which is designed to represent a more accurate representation of real world driving, is implemented in 2017 across all regions, adding further pressure to carmakers in Europe. If this new regulation takes effect in 2017, every carmaker will struggle with CO2 targets for 2021. The EU should implement the WLTP test cycle on a global scale post-2021 – after the next generation of engines have been developed and CO2 targets have been reviewed.”

The table below shows how carmakers rank against their competitors for CO2 emissions: