London’s mayor sees British Prime Minister David Cameron’s replacement of Transport Minister Justine Greening with Patrick McLoughlin as the removal of internal opposition to a third runway at London Heathrow Airport.

McLoughlin assumed the transport minister’s role Sept. 4 in a reshuffle that moved Greening to the Department of International Development. “There can be only one reason to move [Greening], and that is to expand Heathrow Airport,” says Mayor Boris Johnson, a long-time opponent of the third runway.

“It is simply mad to build a new runway in the middle of west London,” Johnson adds.

The mayor has advocated for a new, four-runway airport to the east of London, which he says would “deliver massive benefits in jobs and growth” and address the capital’s constrained airport capacity more adequately than a third runway at Heathrow. “It is time for the government to level with Londoners: [Is it] in favor of a third runway at Heathrow or not?”

The Department for Transport declined comment for this story.

BAA, which operates Heathrow, meanwhile is staying out of the runway debate. “We think all options should be on the table,” a spokeswoman tells Aviation Week. “This could include a new runway at Heathrow.”

The U.K.’s airline industry, however, is heralding McLoughlin’s appointment. “The U.K.’s economy has been hampered by the total lack of policy clarity for hub airport capacity, embracing global connectivity to existing and new markets and the infrastructure to support it,” Mick Carrivick, CEO of industry trade group the Board of Airline Representatives U.K., says in a statement.

“[McLoughlin’s] appointment will provide the necessary momentum required to move the development of key aviation policy away from the delays of the last few years.”