The air in one Sutton street is among the most toxic in London, research has suggested.

Nitrogen dioxide (NO2) levels in Woodcote Road, Wallington, reached more than double EU annual limits on average in the first four months of this year, according to monitoring by King’s College London.

The road was named as one of the 20 pollution blackspots in the capital by campaign group ClientEarth this week.

The street’s NO2 concentration averaged 67 microgrammes per cubic metre between January 1 and April 27, researchers found.

Cllr Nick Mattey, the former Liberal Democrat who joined the Green Party last month after rebelling against council plans for the Beddington incinerator, described the readings as "disgraceful".

He added: “Everyone has a right to breathe clean air. Children are especially vulnerable as they will be exposed to these dangerous pollutants for years to come.

“Too many adults and children are already suffering from asthma and respiratory complaints.”

Peter Mead, a member of the South Wallington Residents’ Association, said he was surprised by the research, which compared levels from 86 monitoring stations across London.

He said: “I didn’t think the area was all that bad. The traffic in Woodcote Road during rush hour is a possible cause. 

“The monitor is right next to a bus stop, so the fumes from the buses passing and stopping could be another reason why the readings are so high – and so perhaps the figures are not truly representative.”

But he added: “More needs to be done to encourage people not to use their cars.”

Researchers found Putney High Street, where NO2 levels are twice as high as Woodcote Road, to be the most polluted road in London. Woodcote Road was ranked 17th.

The High Court last week gave ClientEarth the green light to pursue a judicial review against the Government over its alleged failure to tackle illegal levels of air pollution, which campaigners say cause thousands of premature deaths each year.

Alan Andrews, lawyer for ClientEarth, said: “The Government is dragging its feet whilst Londoners are choking on dangerously polluted air.

“The plans they have come up with are woeful and even by their own admission will not bring pollution down to legal levels until 2025.”