Labour’s plan to gerrymander London’s mayoral election will backfire
Giving the vote to teenagers may be getting the headlines, but Labour are also planning to rig London’s mayoral elections by restoring supplementary voting. It’s a plan based on dangerous assumptions, warms James Ford
Labour is clearly panicking. There is a very real fear that, come 2028, the combination of a deeply unpopular Labour government in Whitehall and a long-serving Mayor drowning in missed housing targets and rising crime will not be a vote winner. Even the possibility of a new Labour candidate for Mayor may not be enough to keep City Hall in Labour’s clutches.
When it comes to shameless election-rigging, the announcement that 16- and 17-year-olds will get the vote by the time of the next election may have attracted all the headlines, but it was not the only devious stratagem that Labour have revealed recently to cling on to power. Hidden in the depths of the English Devolution Bill is a clause to restore supplementary voting in mayoral elections in England, including those in London. (The 2022 Elections Act had, briefly, made all mayoral elections first past the post).
The electoral calculus by Labour is obvious: these voting changes should be enough to stack the deck against the Conservatives and Reform. The supplementary voting system, used for City Hall elections from 2000 to 2021, has always benefited Labour, because Green and Lib Dem voters tend to give their second preference votes to Labour rather than the Conservatives. Indeed, in every mayoral election in London between 2004 and 2021, Labour secured more second preference votes than the Conservatives, often by a significant margin. Conservative strategists have long feared a nightmare scenario where a Labour candidate could become mayor based on second preference votes, even if the Conservatives had effectively won the popular vote on first preferences.
Dangerous assumptions
However, Labour’s strategy is based on a number of dangerous assumptions.
Firstly, Labour is assuming that the approximately 300,000 newly minted teenage voters in London will back Labour overwhelmingly. This is a big assumption and, because pollsters have previously ignored this demographic, there is no data to establish either how teenagers will cast their vote or even how likely they are to vote at all. It should not be assumed that younger voters can resist the siren call of more radical parties.
Secondly, Labour should not assume that London’s vast ‘rainbow coalition’ of progressives – the Lib Dems, the Greens, various fringe socialists and independents – will bail out a Labour candidate by lending them all their second preference votes. Progressives have a wider choice of options than previously, including a growing number of independents (independent candidates came second in six London constituencies last year) and Jeremy Corbyn’s new leftists party may well field a candidate for City Hall (possibly Corbyn himself) which will further complicate things for Labour. No-one should forget that Ken Livingstone became mayor in 2000 as an independent candidate with 39 per cent of first preference votes, pushing Labour into third place with just 13 per cent of the vote.
There is no data to establish either how teenagers will cast their vote or even how likely they are to vote at all. It should not be assumed that younger voters can resist the siren call of more radical parties
Both the Lib Dems and the Greens have become much more significant forces in London elections in recent years, securing 5.8 per cent of the vote in the 2024 mayoral elections, finishing in third and fourth place and collectively accounting for nearly 300,000 votes. In the general election a few weeks later, the Lib Dems took six London seats whilst the Greens came second in a staggering 18 London seats. Leaders of both these parties will be acutely aware that to truly break through they need to get better at taking votes from Labour through a smarter use of tactical voting, including perhaps instructing their supporters to lend their second preference votes to each other rather than Labour.
Labour’s third potentially fatal political assumption is that the rise of Reform is only a problem for Conservatives. Yet the 2025 local elections clearly showed that the Reform insurgency is just as adept at winning over disillusioned Labour voters. Given that the supplementary vote system makes tactical voting not just easy but inevitable, then Reform and Conservative voters will be incentivised to lend each other their second preference votes as the best way to defeat Labour in London. Indeed, if Reform and the Tories can be persuaded to enter a pact to formally encourage their voters to lend each other their second preferences then Labour may find themselves the ones locked out of City Hall.
Politics in London, as in the rest of the UK, is no longer a binary pursuit. Voters have more choices and have shown themselves all too willing to exercise those choices. By returning to a voting system that served them well in the days of two-party politics, Labour may well have put a nail in their own coffin.
James Ford is a former adviser to then mayor of London Boris Johnson