Government approval for Heathrow expansion should only be when the airport can demonstrate it will comply with environmental conditions, a parliamentary committee has concluded.

The Davies Commission, appointed by the government, recommended a third runway at Heathrow as the preferred option for airport expansion in July.

MPs on the environmental audit committee found there was a gap between the Governments current policies on carbon emissions and the policies modelled by the commission, the Guardian reported.

They have called for an approach that delivers aviation emissions no higher than 2005 levels by 2050, which is in line with a target set out by the Climate Change Act.

The Government is expected to announce its decision before Christmas.