The government has backed a third runway to be built at Heathrow Airport.
Officially announcing its support, transport secretary Chris Grayling said it was a "momentous" step.
The government's backing will be subject to a public consultation and has already received criticism from campaigners.
Mr Grayling said: "The step that government is taking today is truly momentous."
"I am proud that after years of discussion and delay this government is taking decisive action to secure the UK’s place in the global aviation market – securing jobs and business opportunities for the next decade and beyond.," he added.
"A new runway at Heathrow will improve connectivity in the UK itself and crucially boost our connections with the rest of the world, supporting exports, trade and job opportunities.
"This isn’t just a great deal for business, it’s a great deal for passengers who will also benefit from access to more airlines, destinations and flights.
"This is an important issue for the whole country.
"That is why the government’s preferred scheme will be subject to full and fair public consultation.
"Of course it is also hugely important for those living near the airport.
"That is why we have made clear that expansion will only be allowed to proceed on the basis of a world class package of compensation and mitigation worth up to £2.6 billion, including community support, insulation, and respite from noise – balancing the benefits and the impacts of expansion."
Among senior Tories who have vehemently opposed a third runway at Heathrow is Uxbridge and South Ruislip MP Boris Johnson , who argued against the proposal during the eight years as London Mayor, and Zac Goldsmith, MP for Richmond Park, who ran for London mayor earlier in the year.
Mr Johnson is expected to deliver a speech later today.
Keith Taylor, a vocal anti-expansion campaigner and Green MEP for the South East who sits on the European Parliament's Transport committee, said: "There are no two ways about it, this is a disastrous decision for the people of the South East, London, Britain, and the planet."
For the latest and reaction on the Heathrow expansion head to our live blog.