Labour’s confidence in the capital city is often misplaced. Those who think that a Sadiq Khan victory in the Mayor of London race next year is inevitable or to be expected are sadly mistaken.

Of the four London Mayor elections there have been, only one has been won by a candidate with the word ‘Labour’ next to their name on the ballot paper. In 2012, Ken Livingstone ran on a Milibandite platform, swapping his usual characterful approach for a tightly run campaign on fare and policing. Both he and Boris ended up with fewer votes than they had received in 2008.

The General Election results in London this year are a little more complicated. On Miliband’s manifesto, and spearheaded by his right-hand man Sadiq, Labour gained seven seats, including four off the Tories, and won a convincing victory across the capital. But Labour’s gains from the Lib Dems were towards the inner city, while the Tories gains came in Kingston, Sutton and Twickenham – suggesting the ‘doughnut’ strategy from ’08 and ’12 is still strong.

Labour failed to take targets Hendon and Croydon Central, while stalling in Wandsworth seats Putney, Tooting and Battersea. Labour will have to think about what it can offer in these increasingly affluent parts of the city – and what is was about the campaigns Sadiq can be closely associated with that failed to convince voters there twice.

The idea of Sadiq Khan, from an family of immigrants and the son of a bus a driver, taking on Zac Goldsmith, a public school boy from a family of billionaires, is a romantic notion for progressives. But painting Cameron, Osborne and Boris as out-of-touch elitists has done little for Labour’s electoral prospects over the past decade. While Khan’s backstory is better than Miliband’s, it is still a risk to simply assume this will work now.

Even the startlingly contrasting turnouts for the Labour and Tory selections could lead us into complacency. Yes, we could read into the paltry 10,000 voters in the Conservative contest that Goldsmith is failing to excite the Tory base, but conflating membership and activism with electoral success is something we should be wary of.

Zac Goldsmith is beatable. He often comes across as pompous and morally superior, and can bang on about issues that people simply don’t care about (I’m looking at you, electoral reform). None of this is to say that Sadiq Khan, who proved this summer his ability to upset the odds. But to call London a Labour city is wide of the mark. If we take City Hall for granted, we won’t take it at all.