Mercedes Benz cars bought in the UK in the past six years are being voluntarily recalled amid a scandal over ‘faked’ emission results.
Owners of almost all models made by Daimler will be asked to return their cars so that engines can be fixed to reduce the amount of harmful pollutants they emit.
German firm Daimler, which makes the vehicles, said the measure to reduce nitrogen oxide (NOx) output will involve no cost to owners.
The action applies to nearly all cars with diesel engines under the EU5 emissions standards - introduced in 2011 - and the more recent EU6 emissions standards.
The required adjustment to the operation of the engine is estimated to take around an hour.
Daimler have yet to confirm how many UK owners are affected, but said one million vehicles in Germany and two million in the rest of Europe are being voluntarily recalled.
170,000 new Mercedes-Benz cars were registered in the UK last year alone.
If the cars could not meet the emissions standards then they should not have been sold to UK consumers. This is because NOX is harmful to humans and the environment and its emission is rightly regulated. Mercedes should come clean with the UK public as to what exactly has occurred when programming the engines.
Diesel emissions have come under huge scrutiny since Volkswagen Group admitted in September 2015 that 482,000 of its vehicles in the US were fitted with defeat device software to switch engines to a cleaner mode when undergoing environmental tests.
Gareth Pope, a group litigation specialist at Slater and Gordon, who represents clients affected by the VW scandal, said: “It is very concerning that another German car manufacturer is facing serious allegations of cheating emissions testing in order to sell highly polluting cars in the UK.
“If the cars could not meet the emissions standards then they should not have been sold to UK consumers. This is because NOX is harmful to humans and the environment and its emission is rightly regulated. Mercedes should come clean with the UK public as to what exactly has occurred when programming the engines.
“News that Mercedes intends to recall the affected cars shows that they are now attempting to make the engines compliant with the regulations.
“Volkswagen are currently doing the same to over 1.2million UK cars, but we have been told by over 5,000 clients that these fixes negatively impact the car’s performance and fuel consumption and in over 700 cases dangerously make the cars go into ‘limp mode’ thereby putting people at considerable risk.”
Dr Dieter Zetsche, chairman of the board of management of Daimler AG and head of Mercedes-Benz Cars, said: "The public debate about diesel engines is creating uncertainty - especially for our customers.
"We have therefore decided on additional measures to reassure drivers of diesel cars and to strengthen confidence in diesel technology.
"We are convinced that diesel engines will continue to be a fixed element of the drive-system mix, not least due to their low CO2 emissions."