A Heathrow Airport spokesperson told Reuters in an emailed statement that the airport had been looking at plans on how to deliver the privately funded expansion project and would present them to the British government in the summer.

The airport, Europe’s busiest, is considering all options before making a final decision, the FT said. One option being explored is an expansion to the northwest, with a shorter third runway to avoid diverting London’s M25 motorway through a tunnel, according to the newspaper.

Last month, Heathrow Airport CEO Thomas Woldbye said a proposal for a third runway would be submitted this summer. His comments came shortly after the government threw its weight behind the project, citing its potential to boost trade and economic growth.

Woldbye said a third runway could be operational by 2035.

The airport’s two runways are full and it can only add passengers when airlines fly larger planes. European competitors Paris and Amsterdam have four and six runways, respectively.