The timescales around any aviation expansion make it possible that not just Goldsmith's but several subsequent mayoral careers may have come and gone before any meaningful progress is made, de-toxifying the issue.

A slightly different scenario emerges if the Davies Commission recommends both more Heathrow and more Gatwick.

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Some say the government could then prioritise Gatwick, but prevaricate further on Heathrow and agree to take a rain-check, which could accommodate not just Goldsmith, but other cabinet figures who don't want any more air traffic out west.

Many think a Davies decision in favour of Gatwick could be the least politically problematic. But the Tory MPs in surrounding constituencies are beginning to mobilise. And what they may lack in cabinet rank they could make up for in attitude. Tell us what you think.