The U.K. government is backing the construction of a third runway at London’s Heathrow Airport, Treasury chief Rachel Reeves said Wednesday in a speech designed to signal to the business world that the new Labour government is serious about turning around the economy.

Plans to expand London's other airports are already further along than Heathrow's and have in the past been viewed as an alternative to a third Heathrow runway. Work is set to start this year to expand capacity at Stansted's terminal. The government is due to make a decision on Gatwick airport by 27 February.

What could a third runway at Heathrow mean for tourism and the climate? Whatever the outcome, it’s still a long way away from happening.