Leading article: No more delays, London needs a new airport

There is only one certainty in the seemingly endless debates about London's airports, and that is that something has to give. Heathrow is already overcrowded and running beyond its capacity, and, with passenger numbers set to more than treble over the coming decades, ignoring the problem will not make it go away.

Indeed, the effects of the current stalemate are already being felt. During the past 20 years, London's status as an international hub has been slipping, and it is increasingly lagging behind rivals such as Frankfurt, Amsterdam and Dubai when it comes to serving fast-growing emerging economies. It is not just a matter of prestige. With more than a third of traffic from passengers transferring between flights, there is real money (and jobs) in a super-connected global network. There is also a boost to London as a business location, which some estimate to be in the billions of pounds.

So far, so good. The problem is the wealth of arguments that stack up against every possible solution. Proposals to increase capacity at Heathrow are a non-starter, ruled out by the Coalition over both the environmental impact and the extra noise pollution over heavily populated west London. An alternative is to build a super-fast rail link between Heathrow and Gatwick. The estimated price tag of £5bn makes the "super-hub" a superficially attractive plan. But, with both airports already running at full stretch, there are few practical benefits without another runway at Gatwick, and the site's planning covenants rule that out until 2019 at the earliest.

The only realistic answer, then, is to build an all-new hub that can take over from Heathrow altogether. There are several options here. One is to build up Stansted, in east London, which has all the apparent benefits of plentiful space and transport links into the capital, albeit ones needing major upgrades. Such a scheme faces opposition every bit as vociferous as that at Heathrow, however, and from a broader cross-section of society. Local groups have already flexed their muscles once. Plans for a second runway were blocked by campaigns to protect not only the area's villages but also prime agricultural land and historic woodland.

Then there is "Boris Island", propounded by the ebullient Mayor of London as a more imaginative option and now to be formally considered by the Government. The scheme is certainly ambitious: a man-made island in the Thames Estuary, costing upwards of £40bn, with the advantage of flight paths along the river rather than over residential areas. Nor is it the only idea of its kind. Sir Norman Foster, the architect, has a similar proposal for the Isle of Grain, also in east London. Both draw praise and censure in equal measure. For every supporter lauding a grand statement of British economic confidence, there is a naysayer decrying the impact on unique avian habitats, the dangers of birds sucked into jet engines, and, of course, the vast cost.

As if the debate itself were not opaque enough, the politics is even more so. With the mayoral race looming, the Tory-led Coalition's non-committal flush of interest in Boris Johnson's plan bears all the hallmarks of electioneering – not least because their Liberal Democrat partners have consistently rejected the idea. But internal wrangling cannot be an excuse for further delay. Neither can opposition from special interest groups. None of the solutions is without drawbacks; but the choice must still be made. And it must be made soon. With Britain in the economic doldrums, and unemployment on the rise, major infrastructure spending would be a welcome boost. The vast Olympic site proves what can be achieved with focused political will. Now the Government must apply the same force to building a new aviation hub in London.