Phil Hornby interviews Prime Minister

As decisions go, they don't get much bigger than this one: where to put Britain's new runway. Gatwick or Heathrow?

The Government couldn't make up its mind, so they asked Sir Howard Davis to make a recommendation.

He did - and gave many Tory MPs the answer they didn't want to hear - Heathrow.

That was last July. So David Cameron said he wouldn't act on the Davis recommendation immediately, but take time to consider. He told the House of Commons he'd make that decision "by the end of the year".

Today we found out: he won't. Or rather, he might not.

What he said, in an interview with ITV News Meridian, is that he wanted to get the decision right, and would make the decision in due course.

What does right mean?

His Chancellor, George Osborne prepared the ground earlier today, when he told reporters that it was important that any decision avoided the risk of a judicial review - which could potentially bog down the go-ahead for years to come.

But some might say "right" means the least problems for the Conservatives, which in the shape of Zak Goldsmith MP - fighting to be crowned as Tory Mayor of London - would mean an emphatic rejection of Heathrow.

Gatwick or Heathrow. Or even back to the drawing board and start again?

The last seems the most unlikely scenario. But in the long and strangled saga of Britain's big engineering projects, the only certainty, is that you need patience.

Meanwhile, for people living under flightpaths in the Home Counties, the uncertainty and the blight goes on.