The airport has begun finalising documents after chancellor Rachel Reeves said the government would support the construction of a third runway, which will likely also mean the construction of a sixth terminal.
Heathrow chief executive Thomas Woldbye said: “We welcome the Chancellor’s recent show of support for a third runway at Heathrow.
“To successfully deliver this project at pace will require policy changes, including on airspace modernisation, planning policy reform and changes to the regulatory regime.
“We are now working with our stakeholders to finalise our plans and will submit our proposal to government by the summer.”