A YouGov poll has found air quality is London’s top environmental concern, in the first survey since the UK government delayed a decision on airport expansion in the South East.

The poll found air quality at 30 per cent and the related issue of road congestion at 29 per cent are the environmental challenges that matter most to Londoners.

YouGov also found Gatwick is the preferred choice for expansion gaining 40 per cen to Heathrow’s 34 per cent.

Prime Minister David Cameron announced just before Christmas an assessment into the impact of air quality would take place before a decision in the summer on whether Heathrow Airport gets a third runway, or Gatwick Airport a second runway.

The government delayed the final verdict to undertake more work on the environmental impacts of expansion, stating: “The Airports Commission’s air quality analysis will be tested using the latest projected future concentrations of nitrogen dioxide.”

Gatwick chief executive officer, Stewart Wingate says: “Air quality is a top concern for Londoners. Nobody living in the capital wants to see air quality deteriorate so it is no surprise to see Londoners supporting Gatwick expansion in poll after poll. Londoners know that Gatwick’s plans come at a much lower environmental cost than other options.

“Crucially, Gatwick expansion would not lead to illegal levels of pollution and so can actually happen. Momentum is with Gatwick as the debate now firmly focusses on what is best for the economy and the environment. The UK economy cannot afford years of more delay – let’s get on and build a new runway at Gatwick.”

Gatwick says it scored best on six out of seven key indicators YouGov monitored including negative impact on quality of life for local residents, encouraging vigorous competition, how quickly a new runway could be delivered, certainty the new runway can be delivered, regeneration benefits to local area, but Heathrow scored higher on economic benefits to UK.