The government said today the need to expand Heathrow is "even greater than originally thought" with London's main airports set to hit capacity sooner than anticipated.
Transport secretary Chris Grayling said updated aviation demand forecasts reveal that the need for more runway capacity is stronger than first thought.
They show that all five of London's main airports will be completely full by the mid-2030s, and four of them within a decade.
Crucially, they also show that the north-west runway scheme at Heathrow is the one which delivers the greatest benefits soonest.
Heathrow runways are now effectively full, while Gatwick grew from 34m to 43m passengers over the past five years and now "operates at capacity over increasingly long periods", according to the forecast. The other three London airports, Stansted, Luton and London City, had a combined increase of 13m passengers in the last five years.
The announcement came with the launch of a new consultation for the public to review new evidence including the updated forecasts. Despite the extra consultation period, the Department for Transport said it remains on track to publish final proposals for expansion in the first half of next year for a vote in parliament.
The public have until 19 December to consider and respond to new evidence in the revised airports national policy statement, including updated long-term aviation forecasts and the new air quality plan.
Grayling said last month a further period of consultation would be needed after the snap election meant the most recent data had not been available for people to review.
MPs had originally been expected to vote on the draft national policy statement late this year or early next, but it was pushed back to the first half of 2018 after the snap General Election.
Today, Grayling said: "Leaving the EU is a new chapter for Britain and provides us with a great opportunity to forge a new role in the world. We are determined to seize that opportunity and having the right infrastructure in place will allow us to build a more global Britain.
"The case for expanding Heathrow is as strong as ever and we want to hear your views on it."
Meanwhile, doubts have been raised as to whether Labour will back the third runway in the parliament vote, while Liberal Democrat leader Vince Cable said at the party conference last month, he wanted his party to remain opposed to Heathrow expansion.
For those in favour of expansion, the concern is centred around progressing with the third runway more quickly.
Jane Gratton, head of business environment at the British Chambers of Commerce, said:
Businesses need Heathrow’s third runway to be delivered as swiftly and smoothly as possible. This outline of next steps is a useful indicator of the remaining stages of the process, but the UK’s business communities will want to see these plans move as quickly as possible.
Building this runway will not only boost business confidence, it will also help firms access export opportunities, and attract investment from both the UK and overseas.
Meanwhile, Lord Adonis, the head of the National Infrastructure Commission, said earlier this month that the stalling on expansion for the airport is "perhaps the most serious infrastructure failure of all".