Environmental lawyers in Germany have described voluntary retrofits for five million cars as a “pitiful” attempt to absolve the diesel industry.

ClientEarth has taken legal action with German organisation DUH in several German regions over illegal levels of nitrogen dioxide (NO2) pollution, which nitrogen oxide (NOx) emissions from diesel vehicles contributed to.

A Stuttgart judge ruled last week (click here for more) that retrofits are an inadequate solution to the issue. He said the legal duty to protect human health from air pollution demands the immediate introduction of localised diesel bans.

ClientEarth clean air lawyer Ugo Taddei said: “This is a pitiful attempt by a discredited car industry to get itself off the hook for creating an endemic problem.

“The solution proposed is far too little, far too late.

"The retrofit would cut NOx pollution by a maximum of 30%.

“That’s a drop in the ocean, considering that Euro 5 and Euro 6 diesel vehicles emit on average five to seven times more NOx than the legal limits.

“Carmakers have come up with a voluntary programme, without a specified time-limit, meaning that people in Germany will continue to be exposed to illegally high emissions from diesel vehicles.

“Retrofitting has just been deemed an inadequate answer to the air pollution crisis by a German court. It cannot form the backbone of the national response to the problem.

“National authorities must roll up their sleeves and truly solve the air pollution problem caused by diesel vehicles in the shortest time possible.”