LONDON: Britain should consider building new runways at London's Heathrow and Gatwick airports, a government commission said, as it published a shortlist of options likely to stir up a long-standing political debate.

The Airport Commission said it would also study an option to build a new airport on the Isle of Grain to the east of London in the Thames Estuary, but added it was not on the shortlist.

The Commission, led by the former head of the Financial Services Authority, Howard Davies, is tasked with making its final proposals on how and where to expand airport capacity by the middle of 2015.

Davies had said in October that Britain will need new runways to remain economically competitive, but the idea of adding more runways in London is unpopular with many voters who worry about aircraft noise, pollution and safety.

The coalition government scrapped plans to expand Heathrow when it came to power in 2010, following through on election pledges from both parties and overturning a decision by the previous government to go ahead with a third runway there.

In its interim report, the Commission listed two options for expansion at Britain's biggest airport, Heathrow. As well as building a new runway, the airport could have also have its current runway extended, it said.

A plan to expand London's third-biggest airport, Stansted, and proposals backed by London mayor Boris Johnson for a new airport on an artificial island in the Thames Estuary failed to make the Commission's shortlist.

Different expansion plans for airport capacity around London have been on and off the table since the 1970s, but with demand for air travel expected to double in Britain to 300 million passengers per year by 2030, the crunch is coming to a head.

Heathrow is the busiest airport in Europe, the third busiest globally and a hub for international flights, but its location near residential areas makes its expansion a toxic issue for local voters, green groups and the Conservatives' coalition partners, the Liberal Democrats.

Lawmakers in Britain's Transport Committee earlier this year recommended that Heathrow be expanded, rejecting the Thames Estuary proposal, citing the cost of new transport links and the impact on wildlife.