A new legal challenge has been launched against the UK Government over its “repeated failure” to tackle air pollution.
ClientEarth said it has lodged papers at the High Court in London and is seeking judicial review.
It follows a win against Environment Secretary Liz Truss at the Supreme Court in April last year.
The ruling ordered the Department for Environment, Food & Rural Affairs (Defra) to come up with new air quality plans to bring pollution down to legal levels by the end of December 2015.
It followed the European Court of Justice ruling against the government for breaching EU limits and ordering it to take urgent action.
However the environmental law firm believes the government is still in breach of the order and its plan “wouldn’t bring the UK within legal air pollution limits until 2025”.
ClientEarth’s new challenge urges the High Court to get rid of those plans, order new ones and intervene to make sure the government acts.
Around 40,000 deaths are estimated to link to air pollution every year.
ClientEarth Lawyer Alan Andrews said: “The government’s plans were an insult to the tens of thousands of people being made sick and dying from air pollution and failed to consider strong measures to get the worst polluting diesel vehicles out of our town and city centres.
“As the government can’t be trusted to deal with toxic air pollution, we are asking the court to supervise it and make sure it is taking action. It is a disgrace that we have had to take further legal action to force the government to protect our health. It must act urgently to tackle this public health crisis.”
Defra insists it is committed to improving the nation’s air quality and fulfilling legal obligations.
It said it has provided more than £2 billion since 2011 to help bus operators upgrade their fleets, reduce pollution and promote the development of clean alternative fuels.
A spokesperson added: “Our plans clearly set out how we will improve the UK’s air quality through a new programme of Clean Air Zones, which alongside national action and continued investment in clean technologies will create cleaner, healthier air for all.”
Last year the World Health Organisation revealed premature deaths as a result of air pollution cost more than $83 billion (£54bn) in the UK.