No Heathrow U-turn, but what next?

So, that's clear then. There will be no U turn.

There will be no eating of prime ministerial words.

There will be no third runway at Heathrow built by this coalition - no ifs, no buts as David Cameron once said.

However, the pressure from business groups for an expansion of Britain's airport capacity remains.

The residents of west London may now be breathing a sigh of relief, but anti-noise campaigners will know that - particularly now there's to be no new runway - there will be renewed pressure for more flights from the existing two, allowing take offs and landings (or so-called mixed mode use).

Those living near Stansted will know that there will be calls for more capacity there.

And the talk of an airport on Boris Island - in truth an idea which long predates the current Mayor of London - will now begin in earnest.

The reason David Cameron made his definitive pledge to oppose a third runway and the reason every major political party has recently opposed it is that airport noise is extraordinarily unpopular, affects people across dozens of constituencies and pledges to halt it can turn elections.

The prime minister may insist that all that happened today is that his ministers re-stated government policy.

However, he will know that he will now come under pressure to answer the question - if not Heathrow, where? And if not airport expansion to revive the economy, what?