Why Theresa May is choosing to fly from Heathrow

Technically the decision on where London should have its next runway will be taken on Tuesday.

So it would be factually incorrect to say that the Government has chosen a third runway for Heathrow, over the competing options of another Gatwick runway or a less ambitious Heathrow expansion.

But I am certain the Cabinet airports sub-Committee will choose that option of a third runway for Heathrow. And Chris Grayling, the Transport Secretary, will announce as much.

Or at least if I am wrong, then so too are most interested MPs, ministers and officials. And they are not.

That said, the Government is desperate to avoid a legal challenge from the disappointed bidder.

So Grayling is following due process, and therefore - to repeat (yawn) - the decision in favour of Heathrow will not be formally and legally taken till Tuesday.

What follows?

Well, as Sir Howard Davies - chairman of the Commission which recommended to a different Prime Minister that Heathrow was the incomparably best choice - said in Monday's Telegraph, there should be mild reassurance to multinational companies that Theresa May is more than talk when she says post-Brexit Britain is open for business (whether Gatwick likes it or not, global capital has a clear preference for Heathrow).

And although the airport will be of greatest benefit to Remain-supporting London, it should become an income-generating asset for the whole UK, so long as it allows more British regional airports to connect to Heathrow as a hub (what is shocking right now is that those regional airports are currently much better connected to Amsterdam's Schipol than to Heathrow).

And what about the more parochial question of whether the PM will be shaken by public protests from the two fundamentalist Heathrow refuseniks in her Cabinet, Boris Johnson and Justine Greening?

Well during the coming year's public consultation on the project, prior to the definitive parliamentary vote likely to be at the back-end of next year, they will be allowed to admit they oppose the new runway when questioned - though they won't be licensed to campaign against it.

This should not be a rerun of the suspension of collective Cabinet responsibility during the EU referendum - which ultimately did for David Cameron.

And for Johnson at least, ambition appears to have triumphed over deeply held conviction, since his people are signalling this is no longer a resigning issue, as and when there is that Commons vote.

Maybe during the coming months of scrutiny, Greening too will discover that running what is arguably the most important ministerial department for our long-term prosperity, Education, trumps her Heathrow phobia.

As for the PM, argy bargy over airports may be a welcome distraction from the more existentially threatening argy bargy over the form and shape of Brexit.