Heathrow and Gatwick recorded their busiest August on record, as both London airports continued their campaigns to be given approval to build a new runway.
The number of passengers who travelled through Heathrow last month stood at 7.3 million, a 0.1% year-on-year increase. Passenger traffic to and from UK destinations declined 10.7% from the corresponding period in 2015, while the number of people flying into Britain's biggest airport was 4.8% lower.
However, the declines were offset by a 9.7% rise in travellers heading to or from the Middle East, while the Latin America market was up 5.8%.
Heathrow's chief executive, John Holland-Kaye, urged the government to approve the airport's plans to build a third runway.
"Now is the time to back the winners in our economy and expand Britain's biggest and most successful port, Heathrow," he said.
"We can get exporters, large and small, from all across Britain connected to the growing markets of the world, and it is urgent that we get on with it. That is why we are looking at options to connect Britain to growth quicker and cheaper."
Meanwhile, Gatwick also recorded its busiest August on record, with 4.8 million passengers travelling through the airport, a 5.7% year-on-year increase. The rise in number was driven mainly by a 51% surge in passengers using North Atlantic routes, while the Irish and British markets recorded increases of 12.8% and 9.1% respectively.
Gatwick chief executive Stewart Wingate said the figures highlighted errors made by the Davies Commission, which in July last year recommended Heathrow should be expanded rather than Gatwick.
"Gatwick is delivering for Britain today and, with a second runway, will continue to deliver the crucial growth we need now more than ever," he said.
"The Airports Commission said that Gatwick could not deliver long-haul routes, yet we have added 20 this year alone, putting us in the premier league of airports in Europe that serve 50 or more long-haul links.
"The Airports Commission also said that we would not serve 42 million annual passengers until 2030, yet we passed this mark just days ago."