The mayoral contest of 2016 has finally taken shape. We can now look forward to Zac Goldsmith (C) Sadiq Khan (L), Caroline Pidgeon (LD) and Sian Berry (G) all vying for the top job over the coming months - an interesting and diverse group of candidates for voters to choose from come 5 May.
But perhaps more interesting is the fact that the Conservative, Labour, Lib Dem and Green candidates are uniformly against further expansion at Heathrow.
Ultimately the decision of where to expand airport provision in the SE is the government’s to take. But whether Mr Khan or Mr Goldsmith end up sat behind Boris’ desk on 6 May, if the government plumps for Heathrow, it seems likely that there will be an almighty battle between City Hall and Whitehall.
Although not a perfect comparison, it is easy to see parallels between Ken Livingstone’s seeking a legal challenge against PPP being employed on the Tube and action that the next Mayor may take.
The fact is though that there may well be a storm ahead of then. It was announced at Conservative conference yesterday that the government will make a decision on airport expansion by December. Zac Goldsmith has very publicly gone on the record and said that if Heathrow is given a green light he will resign and trigger a by-election in his Richmond seat.
Decisions on infrastructure such as airports should be taken in the national interest (of which we will write more later), but it is hard to believe that a Conservative government relishes forcing its own mayoral candidate to call a by-election on his single most defining policy issue.
So, as ever with airport expansion, we are left wondering how on earth this circle can be squared.