The European Commission launched legal action last month against the UK for its failure to cut excessive levels of air pollution.Limits on nitrogen dioxide, a toxic gas which mostly comes from traffic fumes, should have been met by January 2010.
Nitrogen dioxide leads to the formation of ground-level ozone, causing major respiratory problems and premature death, with city-dwellers particularly at risk in the face of high levels of traffic.
The UK Supreme Court has already declared that air pollution limits are regularly exceeded in 16 zones across the UK, the Commission said, including London, Manchester, swathes of England and Glasgow.
Extensions have been agreed with a number of European Union countries with "credible and workable" plans for improving air quality, to allow them until January 1, 2015 to meet the limits.
But the Commission said the UK had not presented any such plan for the areas in question, which are Greater London, the West Midlands, Greater Manchester, West Yorkshire, Teesside, the Potteries, Hull, Southampton, Glasgow, the East, the South East, the East Midlands, Merseyside, Yorkshire & Humberside, the West Midlands and the North East.
As a result the Commission said it was of the opinion the UK was in breach of its obligations under EU law on air pollution, and it had sent a letter of formal notice to the Government which has two months to respond.
If the UK fails to cut pollution it could face a legal process which could result in significant fines.
The Commission is currently taking action against 17 countries over air quality problems, but this is the first to address limits of nitrogen dioxide.