The UK House of Commons voted by a 415-119 margin to approve the building of a third runway at London Heathrow Airport.

After years of debate in the UK over expanding Heathrow, the UK parliamentary vote follows the strong backing for building a third runway at the busy hub by UK Prime Minister Theresa May. The project to build a third runway is expected to cost around £14 billion ($18.5 billion); in addition to paving the runway, it will likely require an expansion of existing terminal infrastructure and a realignment of the M25 motorway. The plan is for the runway to be operational by 2026.

The vote was not without controversy. Britain’s trade minister, Greg Hands, resigned his post ahead of the vote, saying he could not back May on the issue. Boris Johnson, currently the UK’s foreign secretary and formerly the mayor of London—and a long-time opponent of a third Heathrow runway—missed the vote because of a trip to Afghanistan, prompting taunts of “Where’s Boris?” from some Members of Parliament during the vote.

Now part of a government officially backing the plan, Johnson once said he would “lie down in front of bulldozers” to stop a third Heathrow runway.

Progress on the project is expected to continue to be slow, with several environmental and community groups predicted to launch judicial review proceedings against the plan. Also in opposition is International Airlines Group (IAG), the parent group of the airport’s largest operator, British Airways. IAG CEO Willie Walsh has repeatedly questioned the high cost of building a third runway at Heathrow.

Aaron Karp