The government's Heathrow problem

It is the most eagerly anticipated "decision" in Westminster for quite some time. Except when the metaphorical white smoke drifts up over SW1 the likely outcome is that the "decision" is not to make a decision yet at all.

The politics of making a decision on building more runways in the South East of England were always going to be fraught - this time there's the London Mayoral election and a wannabe Tory Mayor, Zac Goldsmith who says he'll walk if Heathrow goes ahead.

There are strong arguments put forward by Gatwick's supporters, concerns over air quality at the West London option, and the implacable opposition from several members of the Cabinet.

By delaying, the government avoids a short term political problem and a pretty acute one at that.

Yet these difficulties are precisely why the government set up the Davies Commission in the first place, independently, to look at the arguments in 2012, to try to take the politics out of a decision that has few political upsides, if any at all, in the short term.

At the time, the government were accused of a fudge, putting off a decision until after the General Election. Well, tonight it looks like there will be a fudge on a fudge, more like the whole sweet shop.

What is interesting is that ministers inside government I've been talking to are frustrated about the indecision, one told me it was "ludicrous".

Another delay certainly is a coup for Gatwick, and will raise doubts about whether Heathrow will ever be a viable option - one minister said it made Heathrow a "dead horse".

But in a wider sense, ignoring the findings of the Davies Commission creates another problem for the government.

It was vaunted as the model for making big decisions that the government professes to really care about. George Osborne told the BBC it was exactly the way he wanted his new Infrastructure Commission to work, that the Davies process had been a success.

Under Lord Adonis's leadership, that Infrastructure Commission is meant to be getting down to business to make independent recommendations on the big projects that the country needs to be competitive.

It doesn't say much for the shiny new model if the government leaves Davies's Heathrow one on the shelf.