Heathrow has pledged to deliver a scheme for a third runway to government by the summer.
The commitment was made after chancellor Rachel Reeves backed expansion of the London hub.
Reporting the airport’s busiest January on record, a statement 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.”
Passenger numbers in January rose by 5% year-on-year to more than 6.3 million – the 11th month in a row Heathrow averaged more than 200,000 passengers a day.
Transatlantic travel was a key contributor of the growth with more than 1.2 million passengers flying between the UK and US, up 8% compared with January 2024.
Heathrow chief executive Thomas Woldbye said: “2025 has started how we mean to go on – serving record breaking passenger numbers and delivering trade and investment across the whole of the UK.
“To ensure we continue on this upwards trajectory, the government has signalled their support for an expanded Heathrow.
“We’ll now work with ministers to progress the necessary policy changes required to advance our growth plans.”
The commitment came the day after British Airways owner IAG, Virgin Atlantic and other airport users urged an “urgent and fundamental review” of Heathrow by the Civil Aviation Authority amid government backing for a third runway.
Meanwhile, Business Travel Association chief executive Clive Wratten said the government’s ambition for a third runway “must not come at the expense of passengers”.
Pointing out that many UK businesses are already facing rising costs and increased operational overheads, he said: “It is crucial that any investment in Heathrow is managed responsibly, ensuring that improvements are not simply passed down through increased passenger charges.
“The BTA urges a clear and fair cost strategy that protects travellers while delivering the modernised infrastructure Britain desperately needs.
“We look forward to working with Heathrow, airlines, hotels and wider industry stakeholders to ensure that the expansion strengthens the UK’s global connectivity without creating unnecessary financial burdens for those who rely on it.”