Decades of squabbling have finally generated positive results for the aviation industry and users of London Heathrow Airport (LHR), Europe’s busiest hub.

Britain’s government on Tuesday gave the nod to a still-controversial plan to build a third parallel runway at Heathrow by calling LHR its favored option for the new concrete. Airport officials say Heathrow, currently running at 99 percent capacity, desperately needs the new runway to stem the tide of mounting air traffic delays.

The cost of the runway will be borne by the private company that now owns the airport, although the airlines fear they’ll pay for the expansion through higher fees. Heathrow’s new runway, once completed, will be the first new landing surface of its size completed in southeast England since the 1940s.

Construction won’t begin before 2021 at the earliest after the UK copes with details of the construction plan and a required parliamentary vote that should occur in late 2017. The battle over a third runway at Heathrow has been simmering since 2003, with parties arguing more recently whether to add the new runway at Heathrow or London Gatwick. Ryanair CEO Michael O'Leary thinks either choice doesn’t go far enough and that new runways should also be added at Gatwick and London Stansted, in addition to Heathrow.

Former London mayor and now UK Foreign Minister Boris Johnson opposes the new runway and plans to continue working against the effort. The Wall Street Journal reported many other conservative members of Parliament also oppose the new runway. A number of local governments in the vicinity of Heathrow have reportedly hired a law firm to also fight the expansion.

Supporters of the new concrete however, say it’s badly needed if London is to compete with expanding hubs like Dubai. The British government says the new runway will generate some $61 billion in economic impact for the country over the next 60 years.