A delay until after the London Mayoral election was always the obvious political choice.  Why the Government promised a decision by the end of the year was always a bit of a mystery.

If the decision is not put back until after the mayoral election, as the BBC is suggesting, then that would be to put Zac under undue pressure and, at the more extreme end, risk him running as a Conservative candidate.

Now all sides can campaign on the air quality issue.  However, Gatwick has been pushing this line for some months now and obviously believe that Heathrow is extremely weak on the issue.

The government will have to endure the embarrassment of yet another delay to a decision but better that than risking losing the mayoralty as far as they are concerned.

A final decision will still be no easier and the longer the delay the more the original timescale that the Davies Commission studied will be questioned.  It said that delivering new capacity by 2030 will be 'crucial' to maintaining the UK's status as a global hub for aviation.

One problem will simply become another.