Campaigners fighting plans for a Tesco in Tolworth were dealt a blow this week when air pollution forecasts came out in favour of the supermarket giant and would not be enough to halt the plans.

The air quality issue was one MP Edward Davey’s key arguments against the supermarket, who feared that the extra traffic coming to Tesco would tip the area around the A3 into unsafe pollution levels, harming the health of local residents.

But in Tesco’s planning application, due to be submitted to Kingston Council today, air quality figures taken by an independent company showed it to be currently below the EU legal limits and will not drastically increase.

Eight receptor tubes were installed around the site to collect data and a computer programme took into account the extra traffic movements for its proposed opening in 2014.

Levels of pollutant PM10 are predicted to be at about 22 micrograms per cubic metre of air, well below the 50 microgram legal limit.

According to the findings by consultants RPS, the Tesco store would only add about 0.1mg of pollution because the proposed new "through-a-bout" design would keep traffic flowing more smoothly.

The amount of other main pollutant nitrogen dioxide is forecasted to be at 36.8 micrograms, also below the 40 microgram EU limit.

But MP Edward Davey said this figure was "within a margin of error" and urged the council to scrutinise them carefully and get a second opinion.

He said: "When I talk to mothers they really are worried about air quality. There are too many cases of children with asthma and that’s the reason why people are so worried about more traffic on the Tolworth roundabout."

His campaign website everylittlehurts.co.uk is due to be relaunched over the coming weeks.

James Wiggam, corporate affairs manager at Tesco, said the air quality argument now "doesn’t really stand", and "in planning terms, air quality wouldn’t be any reason for refusal because of the figures we’ve got."

The plans, which include a 60,000sq ft supermarket and 561 homes next to Tolworth station, remain largely unchanged from those shown at a public consultation in November.

If given the go ahead, Tesco hopes to open the store in 2014 and build the homes afterwards.

Mr Wiggam added: "We’re offering significant investment at a time when investment is difficult to find. Providing 450 jobs is a huge benefit and we hope that is taken into account by the council."

He insisted that the pollution figures produced by RPS "cannot be fiddled" and the company followed guidelines from London Councils.