The European Commission has sent a “final warning” to the UK for failing to address repeated breaches of legal air pollution limits in 16 areas including London, Birmingham, Leeds, and Glasgow.
The UK is one of five countries served with the warning over persistent breaches of nitrogen dioxide levels, which come from sources including factories and vehicles, particularly diesel engines.
Air pollution is linked to the early deaths of about 40,000 people a year in the UK – and causes problems such as heart and lung diseases and asthma.
The Commission said that if the countries failed to take action on the issue within two months, it may decide to take the matter to the European Court of Justice.