There was almost no progress last year in cutting the number of areas that breach the limit for nitrogen dioxide largely produced by diesel vehicles.

The limit came into force in 2010. It will not be met for another decade in some areas, according to analysis by the campaign group Client Earth of official projections of NO2.

The level of NO2 in London last year was more than twice the legal limit, which is 40mcg of NO2 per cubic metre of air. The next most polluted area was South Wales which was 1.6 times the limit, while Glasgow and Birmingham were 1.5 times, Southampton 1.4 and Manchester, Leeds, Edinburgh and Sheffield 1.3.

The figures are in the annual submission the government must make to the European Commission under the EU’s ambient air quality directive.

The submission covers 43 large urban areas and data shows 36 had illegal NO2 levels last year, one fewer than 2017. A small general decline in NO2 emissions, partly due to older diesel vehicles being retired, resulted in Birkenhead, Merseyside, falling under the limit.

This newspaper’s Clean Air for All campaign is calling for clean air zones in all cities with illegal levels of air pollution, with the most polluting vehicles charged daily entry fees as in London. The campaign calls for a Clean Air Act that would require the government to meet the World Health Organisation’s recommended limit for fine particles everywhere by 2030.

The campaign will be the focus of an event in parliament today addressed by Rosamund Kissi-Debrah, mother of Ella, who died aged nine after asthma attacks which doctors linked to illegal air near her south London home.