London should build new runways at its existing airports before building a new air hub to expand capacity, the British government's Airports Commission says.
Britain's politicians have spent years trying to decide how to expand capacity around London and compete with other international air hubs such as Amsterdam, Dubai and Istanbul.
In its interim report released on Tuesday, the government-appointed commission recommended building a new, third runway at Heathrow, extending its existing northern one so it can operate as two separate runways, or building a second runway at Gatwick.
The commission said it did not shortlist the idea of a new hub airport in the River Thames estuary "because there are too many uncertainties and challenges surrounding them at this stage".
However, it said it was not closing the door on the idea and would study the option further in the next six months.
A new estuary airport island, to the east of the city, is favoured by London Mayor Boris Johnson, who argues that a four-runway hub is needed if London is to keep its place as a European financial capital.
He told BBC radio that any expansion of Heathrow would be "consigning millions of people to extra noise pollution" in the west London suburbs.
"A new airport in the inner estuary is the only credible hub option left, and the only one that would uphold this country's claim to be the natural financial, commercial and economic capital of Europe," he claimed.
Heathrow is the world's busiest international passenger airport, while Gatwick, London's second airport, has the world's busiest single-use runway.
