The battle of a third runway at Heathrow in the UK is really intensifying.

Now the British Government Agency in charge of environmental issues – the Environment Agency – has added its weight to the growing criticism by saying the government has failed to prove that expansion plans will not breach EU rules on air pollution.

A dramatic increase in the number of flights could also increase mortality rates across the south-east, the agency warned. The government’s key environmental adviser said the consultation process – which critics have already said is “fixed” in favour of a third runway – had not fully weighed up the potential impact on air quality for people living below the flight path and further afield. A leaked document from the agency also questioned how “robust” the economic analysis for expansion was.

In a damning conclusion, the agency said the consultation process, which ended last month, had not proved that the scheme would not breach EU directives on nitrous dioxide pollution.

Even if the third runway met EU guidelines there would still be a potentially severe impact on the health of people in the south-east, the agency concluded. “It is likely that worsened air quality will result in increased morbidity and mortality impacts.”

Enjoy your flight…