Devolution 4 October 2019 Rory Stewart is running for the London mayoralty. What are his chances? Mayoral elections are the only part of the British electoral system to have successfully returned independents – but it’s still a longshot. Photo: Getty Sign UpGet the New Statesman's Morning Call email. Sign-up Rory Stewart has quit the Conservative Party and will run as an independent candidate for the London mayoralty. It’s a canny move in that the only viable parts of the British electoral system to even semi-reliably elect independents outside the big parties are the United Kingdom’s various mayoral elections. Mansfield was run by an independent mayor from 2002 to May of this year; Ken Livingstone won London as an independent in 2000; George Ferguson was Bristol’s mayor from 2012 to 2016; and Hartlepool elected Stuart Drummond, who first ran successfully as a monkey in 2005 before being re-elected in 2009, remaining the town’s mayor until the post was abolished in a referendum. The London mayoral contest is superficially one that is ripe for a strong independent challenge. The Labour incumbent, Sadiq Khan, is not as popular as he was, and Shaun Bailey, the Conservative candidate, is a very weak candidate, whose campaign seems almost laboratory-designed to quantify the exact size of London’s core Conservative vote. Stewart will receive a lot of free media from both the national press and the Evening Standard, which will help his chances, too. You can just about see the space for Stewart in the marketplace. The charge against Sadiq Khan, fairly or unfairly, is that he has spent too much time being an ambassador for London’s liberal values and not enough time on bread-and-butter issues like transport, crime, housing and the city’s nightlife. The problem with Bailey’s campaign is that he is running both against Khan’s record and against the values that Khan has spent his mayoralty defending. “Sadiq Khan hasn’t done enough as Mayor” is potentially one half of an election-winning platform, but “London doesn’t need to be open and liberal” is an utterly toxic position for a candidate with any hope of winning to hold. Stewart could, in theory, run as the candidate who will stand up for London’s values and who will achieve more as mayor. But the problem with his candidacy is that is looks, to my eyes, to be vulnerable to simply being a carbon-copy of Khan’s campaign, without the benefit of incumbency. In his launch video, Stewart talked about how London is under threat from Britain’s increasing turn towards political extremism. The problem is that, although Khan’s approval ratings have fallen, they have only fallen among London’s remaining Conservative voters – that is obviously a blow to Khan, who for the first two years of his office enjoyed strong support among all voters. But only around a quarter of Londoners now say they will vote Conservative, and Khan can easily do without those voters. They aren't a big enough group to elect an independent candidate. It is also less clear that the remaining 25 per cent of Londoners who say they vote Conservative are going to be a particularly lucrative market for Rory Stewart. Around 15 per cent cent of the remaining Conservative supporters voted Remain – even if Stewart can hoover up all of it, he’s looking at less than five per cent of the vote. That Stewart supported the withdrawal agreeement and is opposed to a second referendum may mean that he can do better with this group than we expect – but in any case, it's simply too small to be of any use. The biggest consequence of his bid might be that it turns Shaun Bailey's candidacy from one that ends in defeat to one that ends in disaster. But I suspect that Bailey is at or near the floor for a London Conservative anyway, and will be hugely dependent on the Conservatives' outer London, more pro-Leave redoubts like Bromley, Havering and Bexley. The one variable is whether some of these voters would prefer a white former Conservative to a black man who is currently a Conservative. There is undoubtedly some joy to be had there electorally speaking, but it's not a path to a majority of the vote or anything like it. In addition, his political appeal rests on the idea that he is a sensible, moderate-sounding guy whose election will “send a message” about London’s values. But London already has a mayor whose appeal is based on the idea that he is a sensible, moderate-sounding guy whose election will “send a message” about London’s values. Stewart’s message that our politics is becoming more extreme is less easy to finesse when you are running against Sadiq Khan, Sian Berry of the Green Party and Siobhan Benita of the Liberal Democrats. It doesn’t even apply to Shaun Bailey: the problem is that he is running a low-wattage campaign that is directly at odds with majority opinion in the capital, rather than that he represents a particularly extreme strand of Conservativism. His main hope will be that, at the moment, it's not clear who the candidate of last resort in London is – who is the person who, if Sadiq Khan is embroiled in some kind of scandal or policy disaster, a majority of Londoners are happy turning to to act as an ejector seat. There’s also a big looming risk for Stewart's candidacy: the general election, which is highly likely to take place before the mayoral election in 2020. Although it wasn’t Change UK’s only problem, that the Liberal Democrats did so well in the local elections meant that it was very clear that they, not Change, were the best and most effective home for pro-European voters in the European elections. I really wouldn’t be at all surprised if the Liberal Democrats emerge from the general election in London similarly boosted; while, for Khan, that the election will be over may have a cleansing effect, allowing him to run as the city’s highest-profile Remainer, free from divides over Labour’s national policy. That speaks to a bigger problem for would-be centrist challengers under our electoral system. The most viable arena for a challenge are our mayoral races. But the great metro-mayoralties are either run by moderates or are in locations of such one-party strength that makes it hard to see how a challenge can succeed. Stewart’s gambit is bold and you can see how it might work on paper – but the journey to making it work in practice is a long one. › Why Tom Watson won’t resign over the Operation Midland inquiry Stephen Bush is political editor of the New Statesman. His daily briefing, Morning Call, provides a quick and essential guide to domestic and global politics. He also co-hosts the New Statesman podcast. Subscribe For more great writing from our award-winning journalists subscribe for just £1 per month!