UK Supreme Court Justices have told the Government it must produce new action plans to cut down illegal air pollution levels by the end of the year.
Speaking in the unanimous decision, the Justices said: "The new Government, whatever its political complexion, should be left in no doubt as to the need for immediate action to address this issue."
The case was fought by ClientEarth, who cite the "right of the British people to breathe clean air", over a five year legal battle.
ClientEarth Lawyer Alan Andrews said: "Air pollution kills tens of thousands of people in this country every year. We brought our case because we have a right to breathe clean air and today the Supreme Court has upheld that right."
The Supreme Court ruling means the Government must start work on a comprehensive plan to meet pollution limits as soon as possible. Among the measures it must consider are low emission zones, congestion charging and other economic incentives.
ClientEarth is calling for action to clean up the worst polluting diesel vehicles, including through a national network of low emission zones.
Cedrec's take
Good news for the Government's targets, bad news for the Government.
The fact is plans have been failing, and when it comes to tackling air pollution, climate change and fossil fuel dependence, the self-proclaimed "greenest ever" Government's policies are lacking and half-hearted.
This will hopefully be the kick needed to produce workable and effective plans, which will help Britain become a world leader in green technologies and environmentally-friendly practices.
It also spells bad news for many policies in several manifestos released over the past few weeks, examples being UKIP's plans to return to coal-fired industries and open-cast mining, and a stop to investment in green technologies such as windfarms on the basis that they are "blights to the landscape". The Conservatives have hedged their policies on such technologies, saying that local people will have the final say regarding whether a windfarm can be built.
Considering how much windfarms contribute to energy output, such statements are worrying. One Party would prefer mines to turbines and another would give the decision-making to homeowners who might consider their property values and bedroom views as opposed to the future of the planet.