Around half of all schools and nurseries in Wandsworth have been found to be in close proximity to London’s busiest and most polluted roads.

Research conducted this year found that living less than 150m away from roads carrying more than 10,000 vehicles a day could account for 15 to 30 per cent of all new cases of asthma in children.

Roy Vickery, Green Party London Assembly candidate for Merton and Wandsworth, said: "This scandalous situation needs action from us all, particularly London’s Mayor and local authorities.”

Concerns about the dangers of long-term exposure to pollution have been amplified by last month’s release of the Government’s own Environmental Audit Committee report, confirming 4,000 deaths in 2008 from air pollution in London alone.

With three A-roads and a bus garage, Putney is potentially one of the worst-affected areas in London.

However Wandsworth Council said it has robust measures in place to reduce air pollution, including countering the school run with initiatives such as discouraging parents from idling their cars near schools and “walking trains” to take children to school.

A spokesman said the council continued to use its air monitoring stations to lobby the Government.

London as a whole breached air pollution levels set by an EU directive earlier this year. The Government and the Mayor have until the end of this month to put an urgent action plan into place, or face punitive action from the European Commission.