Say what you like about Boris Johnson, but, Heathrow aside, the man is clearly a fan of flagship infrastructure projects (not all of them worthwhile of course). Boris has defended Crossrail, championed extensions to the Bakerloo and Northern lines and attempted a raid on the public purse to pay for the £175m garden bridge planned for Lambeth. Boris loves infrastructure projects. A cynic would call them vanity projects. But the mayor is leaving City Hall for good next May and who knows how his successor will view the spread of mammoth projects across the capital?

Whoever wins the mayoral race must be able to step over local concerns and respond to the needs of the city as a whole.

First off, with no disrespect intended towards Caroline Pidgeon, Sian Berry or even George Galloway, I’m assuming the next London mayor will be either Labour or Tory.

Tooting MP, Sadiq Khan was selected to represent Labour on 11 September, largely thanks to his prescient endorsement of a certain bearded socialist and his strong links with London’s Asian community.

Zac Goldsmith had the support of 62 percent of Tory members, according to a Conservative Home poll. His closest rival, Syed Kamall MEP, received just 26 percent. Andrew Boff and Stephen Greenhalgh were both on single figures. So, I think it’s a fair assumption that the MP for Richmond Park will be selected as the Conservative candidate for Mayor of London. And if he keeps his mouth shut and waves politely at cameras, he has a strong chance.

In Khan and Goldsmith, we have two potential mayors whose attitudes towards development and infrastructure can be particularly hard to pin down. London can’t afford to abandon the progress made in recent years. It needs a mayor who can be a real leader and not a glorified councillor: someone with a genuine vision for the city.

Both of them oppose a third runway at Heathrow, although it’s worth noting that Khan’s opposition is ‘newly acquired’ – to put it politely. This is despite the fact that Heathrow runs at 98 percent capacity and is in desperate need of expansion. Of course there are valuable arguments to be made in favour of other airports and for improving rail connections between airports. But surely the need to extend Britain’s biggest and busiest airport is obvious?

While they’ve both been broadly supportive of Crossrail their support is most likely because the potential Crossrail 2 follow up would serve areas near to their own constituencies particularly well.

When it comes to the controversial garden bridge, the two start to differ. Khan has said he would scrap the Thames crossing between the South Bank and Temple, as “it no longer represents value for money”. Goldsmith on the other hand praised it for making London “more interesting, more dynamic, more beautiful.” I’m inclined to agree with Khan; even without the legitimate questions over who’s funding the bridge, you have to consider the fact that it offers very little in the way of environmental or transportation benefits. London doesn’t need a monument to ego that offers nothing to the very people who are paying for it.

I’m not suggesting that a prospective mayor must support every single proposed project in London. But there is clearly a tendency for many politicians to descend into naïve populism whenever an issue becomes even the slightest bit contentious. A “say whatever gets the most cheers and be done with it” sort of attitude typified by people such as Andy Burnham, who is most likely plotting as we speak to succeed Jeremy Corbyn as Labour leader.

Maybe this is what you get with only current and former councillors and MPs standing for City Hall: too much localism not enough grit. Perhaps the London mayoralty needs a Michael Bloomberg to transcend party politics and NIMBY delusions? Boris isn’t perfect, but he’s a champion of progress. If his successor is to engender anywhere near the same admiration from Londoners of all colours, he’ll have to embrace what’s right for London over the long term.