Britain is being taken to court by the European Commission for breaching EU air quality laws.
Levels of dangerous nitrogen dioxide (NO2) peaked as high as 102 micrograms per cubic metre in 16 locations in the UK in 2016.
The EU limit is 40 micrograms.
Karmenu Vella, the EU’s environment commissioner, said Britain had failed to provide “credible, effective and timely” plans to cut pollution.
London, Birmingham, Leeds and Glasgow were among the locations where breaches were recorded.
France and Germany have also been referred to the European Court of Justice, but neither reached the pollution levels of the UK.
Mr Vella said: “The decision to refer member states to the Court of Justice of the EU has been taken on behalf of Europeans.
“We have said that this Commission is one that protects. Our decision follows through on that claim.
“The member states referred to the Court today have received sufficient ‘last chances’ over the last decade to improve the situation.
“It is my conviction that today’s decision will lead to improvements for citizens on a much quicker timescale.”
The UK Government blamed EU standards for diesel cars failing to deliver expected reductions.
And it pointed out the UK was one of 22 EU states exceeding NO2 limits.
A spokesman for the Environment Department said: “We continue to meet EU air quality limits for all pollutants apart from nitrogen dioxide, and data shows we are improving thanks to our efforts to bring levels of NO2 down.”
London Mayor Sadiq Khan welcomed the EU’s action, saying UK ministers’ “disregard for the nation’s health is shameful”.
Neil Parrish, a Conservative MP and chair of the Commons environment committee, said: “It is astonishing that, despite a series of legal defeats, the Government has consistently failed to come up with a coherent and effective plan to tackle this national health emergency.”