(Bloomberg) -- London’s Heathrow Airport intends to speed up spending on its controversial third runway, even before getting approval for the 14 billion-pound ($18 billion) project, according to the industry regulator.

Europe’s busiest airport plans to boost early spending to 2.9 billion pounds, in 2014 prices, so it can stay on schedule for a planned 2026 opening, the Civil Aviation Authority said in a consultation document on its website. The costs will be incurred before the airport wins permission to build the runway, which the operator expects to happen in late 2021, according to the document. The Financial Times reported the plan earlier.

The CAA has asked Heathrow to “consider different options for this spending” noting the risk that passengers may end up having to pay costs for a runway that ultimately isn’t built. The airport has been struggling with capacity constraints as it awaits permission for the new runway, even after spending more than 10 billion pounds on upgrades and expansion over the past decade.

Read also: Heathrow Runway Overcomes Opposition of Mayor, Protesters

Heathrow’s budget for the new runway remains unchanged, the CAA said. The airport operator’s total capital-spending plans through 2050 are about 32.5 billion pounds, as it works to boost capacity to 142 million passengers per year.

To contact the reporter on this story: Elena Mazneva in London at emazneva@bloomberg.net

To contact the editors responsible for this story: Andrew Davis at abdavis@bloomberg.net, Neil Denslow, James Amott

©2019 Bloomberg L.P.