The plans revealed by Heathrow were welcomed by business groups and airline companies.
A joint statement from the Confederation of British Industry, British Chambers of Commerce, MakeUK, Federation of Small Businesses and Institute of Directors, said it was “an investment in the nation’s future”.
It added: “The benefits are clear: for exporters, it opens up vital access to major and emerging markets; for visitors, it enhances global and domestic connectivity; and for businesses, it unlocks billions in private investment, strengthening supply chains, creating jobs, and driving skills across the country.”
John Dickie, chief executive of BusinessLDN, said as the airport was currently operating at full capacity, the expansion would give businesses “better connectivity to overseas markets and support Britain’s growth”.
He added it would also help achieve the government’s target of 50 million international visitors per year to the UK.