The government has finally given the green light to the plan to build a third runway at Heathrow after years of delays and opposition from campaigners.
The transport secretary, Chris Grayling, told MPs the announcement represented a “historic moment” that showed ministers had a clear vision to build “a Britain fit for the future”. Critics claim it will damage the environment and could end up costing the taxpayer billions.
The government will face tough opposition from Conservative MPs despite confirming it will impose a three-line whip for a crunch vote in the Commons, meaning it could be forced to rely on the support of Labour and the Scottish National party.
Theresa May wrote to ministers confirming that those with longstanding objections to a third runway would be permitted to restate their views in their local media, but not to campaign actively against the decision.
The Guardian understands that Boris Johnson, the foreign secretary, who has said he would “lie down in front of bulldozers” to prevent the project, is not planning to resign over the issue, raising the likelihood of him being abroad for official business on the day of the vote.
May and her ministers backed the expansion of Heathrow at a cabinet subcommittee meeting on Tuesday morning, with the decision to improve air capacity in London and the south-east then approved by the full cabinet.
It will now go to a vote in parliament, which will be held within 21 sitting days, though sources suggested it would be sooner to avoid any rebellion gathering momentum. One cabinet source told the Guardian it could be on 18 June.
In a statement to MPs, Grayling said: “Today I’m laying before parliament our final proposal for an airports national policy statement which signals our commitment to securing global connectivity, creating tens of thousands of local jobs and apprenticeships, and boosting our economy for future generations by expanding Heathrow airport.”
Whitehall officials have said there is no alternative option if MPs block the third runway plan, and that airport expansion would simply be kicked into the long grass once again.
Government insiders said Tory whips were relatively confident about winning the vote, but admitted they had concerns that Labour could come out against expanding Heathrow.
Andy McDonald, the shadow transport secretary, said his party would consider whether its four tests had been met. However, one senior Labour figure said: “They have not been met yet.”
Labour faces its own splits on the issue, however, with the shadow chancellor, John McDonnell, tweeting: “I remain implacably opposed to expansion at Heathrow and after listening to the transport minister, Chris Grayling, today I am even more convinced that this would be a costly, environmental and social disaster that will never be built.”
However, many backbench Labour MPs and the unions support the expansion plans. Len McCluskey, general secretary of Unite, the party’s biggest union backer, was quoted in Heathrow’s official response to the announcement.
He said: “Heathrow expansion, one of the biggest construction projects in Europe, answers the demands of many Unite members across the UK – for more skilled, well-paid and sustainable jobs … I would strongly urge MPs to vote in favour.”
Grayling admitted the decision had not been easy and that he recognised the strength of feeling it had generated in local communities, “but this is a decision taken in the national interest and based on detailed evidence”.
He told MPs: “The time for action is now. Heathrow is already full and the evidence shows the remaining London airports won’t be far behind. Despite being the busiest two runways in the world, Heathrow’s capacity constraints mean it is falling behind its global competitors, impacting the UK’s economy and global trading opportunities.”
The transport secretary said the third runway would bring benefits far beyond London and that improving regional connectivity was one of the key reasons for backing the plan.
He confirmed that up to £2.6bn in compensation would be available for local people, including for noise insulation, and the third runway would be granted planning consent only if it met the UK’s air-quality commitments.
He said the new runway, which could be completed by 2026, would be privately funded, although critics claim it could lead to up to £15bn in extra taxpayer-funded transport costs.
However, Grayling appeared to water down his previous commitment to guarantee 6.5 hours at night with no flights, simply saying that mitigation measures were “expected to include” a quiet period overnight.
The statement also appeared to pave the way for Heathrow to raise the number of expected flights, with “at least 260,000” more movements from a third runway, rather than capping the airport’s total at 740,000 a year as opponents believed.
“I hope MPs will feel the scheme is crucial to our national interests, that we need to work together to deliver it in order to create what I believe is an absolute vital legacy for the future of our country,” he said.
However, McDonald said Labour would only back the third runway if the proposals met the party’s four tests on capacity, noise and air quality, climate change and economic growth.
“We owe it to future generations to get all of these factors absolutely right, but if the correct balance isn’t found then the law courts will quite rightly intervene,” McDonald told MPs. “We will not rely on the assurances of the secretary of state for transport, whose assurances are sadly not worth the Hansard they are printed on.”
Justine Greening, a former transport secretary and leading opponent, questioned whether the government had plans in place to prevent the taxpayer being exposed to financial liabilities should it change its mind in future.
“This decision is not only wrong for the UK and its competitiveness, it’s also wrong for London communities who will be blighted by the pollution from Heathrow,” she said.
Caroline Lucas, the Green party MP, questioned the transport secretary’s commitment to the environment as he had not uttered the words “climate change” once during his statement.
Quick guide Heathrow – third runway
Has Heathrow's third runway been approved?
The cabinet has endorsed a revised national policy statement on aviation, whose key point is to enable Heathrow expansion with a third runway. A wider vote will now take place within 21 sitting days in parliament, or by 10 July.
What will happen next?
The parliamentary vote is now the big moment. Heathrow is confident it has enough MPs to back it, as long as Labour does not whip its party to vote against. And even then some might defy the leadership.
And then they start digging, demolishing houses and rerouting the M25?
It’s likely to be another three years before any spades hit the ground. Heathrow's detailed plans will be subject to public consultation and a planning inquiry. That could all be delayed by judicial review. A separate review of flight paths and airspace is also due.
But if all that goes smoothly?
Then the government would finally sign off the planning permission in 2021, for a runway to be built as early as 2025.
The Tory backbencher Zac Goldsmith, who forced a byelection over the issue, accused the government of writing “a whole book of blank cheques” signed by the public to deliver the project.
Unions quickly weighed in to urge MPs to back expansion, with Labour’s support potentially crucial to carry the vote. As well as Unite, the GMB said the case was compelling and would deliver 180,000 jobs nationwide.
John Holland-Kaye, Heathrow’s chief executive, said MPs’ votes would “connect all of Britain to global trade, increase competition and choice for passengers and create tens of thousands of new skilled jobs for future generations”.
Among those living in the shadow of the proposed new runway there was defiance, frustration and anger.
Roy Barwick lives in Harmondsworth, one of the villages being told to make way for the project.
He described the way residents have been treated as “an absolute disgrace”, adding: “My family all live here in Harmondsworth. My children and grandchildren occupy four houses and we will all be forcibly evicted from our homes.”
Neil Keveren, whose home will face the boundary fence of the new runway, said residents felt “100% betrayed” and vowed that “a legal challenge will start next if the MPs fail us”.
Business groups have long called for expansion. The director general of the British Chambers of Commerce, Adam Marshall, said: “A resounding vote for Heathrow expansion in parliament would do more than just unlock this crucial infrastructure project, as it would give a huge boost to business confidence and investment at a time of significant change.”