The government's leading advisor on climate change has denied a report that he endorses the case for a third runway at Heathrow.

Climate Change Committee chairman Lord Adair Turner dismissed the report in The Guardian yesterday as "completely misleading". He had been reported as saying aviation could continue to expand while the world cut greenhouse-gas emissions elsewhere.

Turner's view carries weight as he also heads the Financial Services Authority and is a former chairman of the Confederation of British Industry.

His rebuttal came as shadow transport secretary Theresa Villiers reiterated Conservative opposition to Heathrow expansion. She said: People do not want a third runway, we do not need a third runway and under a Conservative government there will not be a third runway."

Villiers added: "The government's plans for expanding Heathrow will breach European Union rules on other types of pollution which become legally binding in 2010."

Transport secretary Geoff Hoon is due to announce whether to proceed with expansion before the end of the year. The government has long favoured building a third runway, but major carriers and Heathrow operator BAA are increasingly concerned expansion may not get the green light.