(Bloomberg)—London Mayor Sadiq Khan asked Britain’s new prime minister to approve adding a runway at Gatwick Airport in the southeast of England and bypass expansion plans for Heathrow, Europe’s busiest airline hub. “Gatwick is the front door to London for millions of visitors to our city,” Khan said Friday in a statement. Prime Minister Theresa May “has a very important decision to make regarding new airport capacity, and I urge her to rule as swiftly as possible in favor of a second runway at Gatwick, which would bring substantial economic benefits.” Khan’s push comes just two days after May became took her post amid the political upheaval caused by the U.K. referendum last month to quit the European Union. A decision on whether to build a third runway at Heathrow or a second at Gatwick was due to be made under former Transport Secretary Patrick McLoughlin a week after the ballot, but he postponed it until “at least” October, assuming that a new government would only take office in September. Operating company Gatwick Airport Ltd. outlined plans in Khan’s statement to spend an extra 200 million pounds ($268 million) adding parking stands for aircraft, expanding departure lounges and immigration halls and upgrading shopping facilities, bringing investment from 2009 through 2021 to 2.5 billion pounds. McLoughin’s successor as transport minister, Chris Grayling, hasn’t publicly endorsed either the Heathrow or Gatwick project. May’s constituency in the western London suburb of Maidenhead is located under a Heathrow flight path. Khan’s predecessor as mayor, newly appointed U.K. Foreign Secretary Boris Johnson, was a staunch opponent of expansion at either airport, campaigning instead to build a new one east of London in the River Thames estuary. Other politicians remain split on where to add flight capacity even after a state-appointed commission came out in favor of expanding Heathrow. The airport, which served 75 million passengers in 2015, is located in a more urban area than Gatwick, making emissions and noise pollution a greater political concern. Heathrow’s operating company said in response to Khan’s comments that Britain’s pending departure from the EU, known as Brexit, make the commission’s recommendation “even more persuasive,” based on business travel and air freight needs.