It’s another milestone in delivering a final planning decision in 2029, with the aim of meeting key tests on noise, air quality, climate and economic growth.
Supporters of Heathrow expansion say it will attract international investment, boost Britain’s connectivity to new markets, and could deliver more than £40 billion of benefits to the UK.
Critics see it different, however.
Hayes & Harlington MP John McDonnell said: “[It] is economically, environmentally and, on health grounds, a non-runner, with the risk of an HS2-style scale of abortive costs and burdens on taxpayers.”
Hillingdon Council leader Steve Tuckwell added: “The timing and structure of this consultation risk creating the impression the Government is more interested in securing a particular outcome than listening to the communities affected.
“Hillingdon remains firmly opposed to a third runway. We are carefully scrutinising the consultation documents and will respond robustly.”
The airport handles more flights than any other two-runway airport in the world, with a record 84 million passengers using it last year.
The consultation proposes that any scheme must have a clear strategy to create jobs and realise the economic benefits of expansion.
It should also be compatible with climate targets, not breach legal air quality limits, and ensure noise emissions do not worsen for neighbouring residents.
Transport Secretary Heidi Alexander said: “We’re a government of builders, not blockers, taking the steps needed to unlock billions in investment, boost growth, and create thousands of local jobs.
“Today’s consultation is a positive step towards realising the benefits of a third runway, by giving businesses, communities, and the public the chance to help shape this key project.”