There is enough UK airport capacity to cope with its needs if it is utilised properly, the London Assembly claims today.

Heathrow, which uses 99% of its runway capacity, could serve 20 million more passengers a year without the need for a new runway if bigger aircraft are used, the Assembly’s transport committee says in its submission to the government’s independent inquiry into airport capacity.

Excess capacity at London’s other airports means new runways are not needed, it claimed.

Last summer, 12% of runway slots at Gatwick were not used, 47% at Stansted and 51% at Luton, according to the committee.

“The Airports Commission must examine whether better use of existing airport capacity could be an intelligent, cost- effective alternative to building new airports or runways,” said transport committee chairman Caroline Pidgeon.

“Currently London sees 130 million passengers traveling through our airports each year. The challenge for the government and decision-makers is to find the best way to support the UK’s economy globally while ensuring Londoners are not adversely affected by worsening noise and air pollution.”

The committee report said: “If the Airports Commission finds that there is a need to increase airport capacity, it should rule out the expansion of Heathrow airport.

“It should also make clear in its interim report its criteria for shortlisting any other options, which should cover cost and funding; how the option would meet local demand for air travel; the effects on Heathrow; airspace implications; and the potential environmental impacts.”

The committee said it is “not certain” that demand for air travel will increase as much as previously predicted and said London’s airports may not reach capacity until 2040 rather than 2030.

“Each airport in London, including Heathrow, serves a geographically distinct local market and it is this market which is a major influence on where airlines fly to,” the committee said.

Stansted told the committee it could attract 1.5 million more passengers a year if the train journey to central London was cut to 30 minutes from the current 45.

The committee raised concerns about London mayor Boris Johnson’s proposal for a new hub airport in the Thames estuary.

The economic impact of the resulting closure of Heathrow, an increase in airplanes flying over central London and how the £80 billion cost would be met would need to be considered by the Airport Commission alongside the dangers of birdstrike from thousands of migratory birds in the estuary, it said.