Congratulations to Sadiq Khan. His selection adds another interesting candidate to the race to be London’s next Mayor. The Green Party candidate Sian Berry has a worthy opponent in Khan, the man who infamously led Labour’s anti-Green attack unit, during the recent General Election campaign…

The selection of Sadiq Khan as Labour’s candidate is welcome in one particular respect: it helps to maintain the principle that no-one can be elected Mayor of London if they support the expansion of Heathrow airport. Ken Livingstone and Boris Johnson established that principle between them, but Tessa Jowell would have broken it and would therefore have had a hard time against the likely Tory candidate, Zac Goldsmith, who is vociferously opposed to the airport’s expansion.

This may make a difference to the overall result. Second preferences count in this election. If the Greens come third – and of course, in this remarkable era of surges, of the seemingly impossible becoming possible, they may come first or second – but, if they come third then their voters’ substantial number of second preferences will be redistributed. Tessa Jowell would have had very little credibility for this part of the electorate.

However the situation with Sadiq Khan is more complex. He opposes the expansion of Heathrow – but favours expanding London’s other big airport at Gatwick. According to an Evening Standard report , Khan says he has “thought long and hard” about what they describe as the “aviation capacity crisis”. He stressed he was “not anti-aviation” and is in support of a new runway being built to expand Gatwick.

Of course the Standard often misrepresents people and gets things wrong. But on the same date Khan himself wrote an article for City AM in which he said: “I believe the answer to the airport capacity problem lies in expanding Gatwick and making Heathrow better, not bigger”.

Khan may have thought long and hard about airport capacity, but has he given any thought at all to dangerous human-triggered climate-change? There are many reasons for opposing Heathrow expansion, including noise, air pollution, road traffic congestion, and the destruction of housing. Khan shows every sign of taking those arguments seriously; but if he was also opposed to enabling more take-offs and landings at Heathrow because of the increasing contribution aircraft emissions are making to climate change, he would be opposing the expansion of Gatwick too.

The only intellectually consistent position from which to champion airport expansion is the systematic denial of climate science. There is no sign that Khan takes this view. Therefore, his opposition to Heathrow-expansion runs the risk of being in the end nothing more than NIMBY-ism.

For the sake of building cross-party co-operation against the Tory Government, it would be good if Green voters felt they could give a Labour candidate their second preferences. But what will Sadiq Khan do to earn them? Without standing firm against London-airports-expansion full stop, as Greens stand firm, it’s as yet hard to say. And, given that Khan is likely to be up against the renowned green-leaning Zac Goldsmith, he will have his work cut out, frankly.

The reality is that, as we lean into this mayoral election race in London, the only thing that Greens can say with one clear voice is: vote Green. Vote for our superb candidate, Sian Berry. If Corbyn can come from being a complete outsider to being the hot favourite to win the Labour leadership, then surely it can be time too for Londoners to get behind the only candidate who can be trusted to stand firm against any more crowding of our skies — and of our atmosphere – with pollution. Let the Green momentum build…

One of us (Read) will be speaking alongside Sian Berry in London on Saturday Sept. 12th, on precisely this issue. We hope perhaps to see you there.

Victor Anderson is a former Green Party Member of the London Assembly. Rupert Read is the Green Party’s national Transport Spokesperson. Both are core members of Green House (www.greenhousethinktank.org )