Heathrow Airport has approved funding to begin work on a planning application for its long-planned third runway.

The decision clears the way for detailed planning work as the airport works towards securing consent by 2029.

Heathrow said expansion remains the Government’s flagship growth scheme, unlocking billions of pounds of privately funded construction work across the supply chain while boosting airline competition and strengthening global trade links.

Despite the board backing, the airport stressed the project will only proceed once a clear regulatory and policy framework is locked in.

Shareholders continue to support expansion, but a sequence of decisions next year will determine whether the scheme can move into its next phase.

In spring 2026, the Civil Aviation Authority is expected to confirm how early development costs can be recovered.

Over the summer, the Department for Transport will publish a draft Airports National Policy Statement, alongside a CAA decision on the long-term regulatory model needed to attract private investment.

Parliament is then due to vote on the final policy statement in the autumn, setting the planning framework for the project.

Heathrow chief executive Thomas Woldbye said the board’s decision keeps the project on track to secure planning permission by 2029 and reflects renewed ministerial backing for expansion.

He added:”“Heathrow expansion is a critical national project and a central part of our journey to make Heathrow an extraordinary airport, fit for the future.

“Maintaining momentum will mean the CAA and Ministers remain focussed on securing the benefits of the project by meeting vital milestones in 2026 that are essential to enabling the next phase of delivery.”