The government is still not showing it is tackling major air pollution concerns if a third runway at Heathrow is built, a new report argues.
Air quality, carbon emissions and aircraft noise have all been flagged up as areas which need more attention before expansion of the west London hub goes ahead.
The report by the cross-party Environmental Audit Committee (EAC) called on ministers to set out how the third runway project can go ahead without increasing the number of serious breaches of air quality limits.
It claimed there is no agreement between the government, Transport for London and local authorities on the cost of improving road and rail links.
Car journeys are the main contributor to airport-related pollution, and MPs said Heathrow's pledge for there to be no extra cars on the road despite hundreds of thousands more flights each year will only have credibility if it is "legally enforceable".
The findings have once again angered campaigners against the decision, who felt the government has been caught not taking concerns seriously.
Rob Barnstone, campaign coordinator for Stop Heathrow Expansion, which represents communities around Heathrow , said: "This report is damning for both the government and Heathrow.
"It shows that for all their crowing about how Heathrow expansion can be delivered within air quality limits, carbon budgets and with range of mitigation measures on noise, the truth is, unsurprisingly, that it can’t.
"A third runway is proving more undeliverable by the week."
Keith Taylor, Green MEP for the South East and a member of the European Parliament's Environment Committee, said the report was further proof that "Heathrow expansion is an unnecessary environmental disaster in waiting".
This report is published two weeks after the government launched a public consultation on a third runway at Heathrow earlier this month, which ends on May 25.
The Department for Transport published a draft National Policy Statement (NPS) for airports expansion on February 2 2017.
Since the committee’s report was agreed, the Liaison Committee has designated the Transport Select Committee to scrutinise the draft National Policy Statement.
John Stewart, the chair of HACAN, the campaign group which opposes Heathrow expansion, said: "The committee is saying in no uncertain terms that both the government and Heathrow Airport have got to up their game big-time if they are to have any chance of getting a third runway.
"They have got to prove they can deliver on noise, climate and air pollution, not just say they can."
But not everyone has seen the findings as a sign for the runway not to be built.
Philippa Oldham, Head of Transport at the Institution of Mechanical Engineers, said: "The new runway at Heathrow will be hugely valuable to increasing trade and supporting the UK’s growth and productivity, particularly after the UK leaves the European Union.
"The challenge to doing this, while mitigating the environmental impact, is big but not insurmountable."
Tuesday (February 21) saw the Heathrow tunnel blocked once again by protesters vehemently against the decision to expand in west London.
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