The House of Commons voted by a majority of 296 in favour of building a third runway at Heathrow Aiprort .
The vote late on Monday night (June 25), was followed by an immediate threat of legal action by mayor Sadiq Khan, Greenpeace and four London councils, Wandsworth, Richmond , Hillingdon and Hammersmith and Fulham .
It is not yet clear how the legal action will impact the process, but Heathrow Airport Limited hope to apply for planning consent after another round of public consultation, with construction forecasted to begin in 2021 and the completion of the £14 billion runway project by 2026.
The idea of expansion has been around for decades, but was first seriously discussed in the Commons during Tony Blair's Labour government.
Since then, the issue has proved highly divisive locally with several pro and anti-expansion pressure groups cropping up.
Several west London MPs have voiced very vocal opposition of the runway, including Boris Johnson who promised, after winning his Uxbridge and South Ruislip seat in 2015, to "lie down in front of those bulldozers" to prevent expansion going ahead.
However the Foreign Secretary was in Afghanistan for meetings when the vote was scheduled to go ahead. Had he been in the country, he would have had to resign his cabinet post as convention dictates you must do before you vote against the government.
Writing the in Evening Standard to his constituents, he said: "My resignation would have achieved absolutely nothing."
He went on to say that the insistence of Hillingdon councillors for him to continue as their MP was a major factor in his decision not to resign over the vote.
"I have long been an opponent of a third runway at Heathrow and that is why I am not voting for it tonight," wrote Johnson.
"I have made clear my opposition since joining the Government, and I will continue to lobby colleagues from within government.
"Some of my critics have suggested that I should resign over the issue. No doubt they have my best interests at heart.
"But it is clear from what is likely to be a large majority of MPs who are in favour of a third runway that my resignation would have achieved absolutely nothing.
"Hillingdon council have been emphatic that they would rather have me in the Cabinet and fighting for their cause on this and other issues."
Meanwhile Chelsea and Fulham MP Greg Hands resigned from his International Trade Minister posting in order to vote against the third runway.
In a tweet on Sunday, Mr Hands wrote pointedly: "Great to arrive back in the UK at Luton Airport in time for the (England) match today and to vote against Heathrow expansion tomorrow.
"I wouldn't want to be abroad for either of those commitments."
Overall, 415 MPs voted in favour of expansion and 119 against. Within the Conservative Party , just eight MPs defied the whip and voted against the government.
Labour had declared the party was against expansion but did not whip its MPs to tell them how they should vote. Just 94 Labour MPs voted against expansion while 119 were in favour.
Labour MP Tulip Siddiq and Conservative Nick Hurd did not vote. Hurd, Minister for Policing and the Fire Service, has in the past been a vocal expansion opponent, writing on his website "I have always opposed expansion of Heathrow Airport".
How did your MP vote?
Constituency | MP | Party | Vote |
Brent Central | Dawn Butler | Labour | Against |
Brent North | Barry Gardiner | Labour | Against |
Brentford and Isleworth | Ruth Cadbury | Labour | Against |
Chelsea and Fulham | Greg Hands | Conservative | Against |
Cities of London and Westminster | Mark Field | Conservative | For |
Ealing Central and Acton | Rupa Huq | Labour | Against |
Ealing North | Stephen Pound | Labour | For |
Ealing Southall | Virendra Sharma | Labour | For |
Feltham and Heston | Seema Malhotra | Labour | For |
Hammersmith | Andy Slaughter | Labour | Against |
Hampstead and Kilburn | Tulip Siddiq | Labour | |
Harrow East | Bob Blackman | Conservative | Against |
Harrow West | Gareth Thomas | Labour | For |
Hayes and Harlington | John McDonnell | Labour | Against |
Hendon | Matthew Offord | Conservative | Against |
Kensington | Emma Dent Coad | Labour | Against |
Richmond Park | Zac Goldsmith | Conservative | Against |
Ruislip , Northwood and Pinner | Nick Hurd | Conservative | |
Twickenham | Vince Cable | Liberal Democrat | Against |
Uxbridge and South Ruislip | Boris Johnson | Conservative | |
Westminster North | Karen Buck | Labour | Against |