The First Past The Post electoral system leads to some pretty stagnant thinking when it comes to the main political parties. They’re basically all chasing the votes of the same home-owning swing voters in the provinces with a garnish of xenophobia on the side to win back the Ukip waverers. But the electoral calculus is changing and we’re starting to see politicians respond to this.

Recently we crunched the numbers from the past two census returns, remapping the data against the current parliamentary boundaries. And we found that by the next census in 2021, roughly 104 parliamentary seats will have a majority of households that are renting. Unsurprisingly, 49 seats, almost half the total, were in London, with most of the rest in other urban areas.

This leaves the parties with a conundrum; can you be a party that is for provincial baby boomers and the urban young at the same time? And with the London election only one year after the general election, this isn't an abstract question.

The mayoralty can only be won by Labour, the Conservatives or an insurgent independent candidate - maybe a Green. The Conservatives are facing a problem in the form of a rapid decrease in the number of homeowners compared to renters, however, with a colourful candidate and a low Labour turnout, they can still win.

Labour on the other hand has a bigger problem. Its lack of a coherent housing policy lets down the 35% of Londoners who, according to Ipsos Mori, say that housing is their number one issue of concern. A failure to address this is precisely what will give the Conservatives the low Labour turnout that they need.

Most of Labour's putative mayoral candidates have clearly recognised that they have no chance of winning if they toe the party line and Hackney MP Diane Abbott has gone further than the rest with her publication this week (with us) of her proposal for a modern take on rent controls.

This plan sets a low cap, related to council tax bands, but allows landlords to breach that cap on the condition that they pay 50% of the excess into a social housebuilding investment fund controlled by the Mayor.

The graceful effect of this is that landlords either charge low rents, or they fund housing supply, which will bring rents down, creating a long term market convergence towards the capped price. The more they charge, the more they fund truly affordable housing.

We're happy to work with any mayoral hopeful (OK, not the BNP) to come up with great housing policies. But Labour will scupper the chances of its own candidate if they fail - potentially in government - to win credibility with London's renters.

Failing to address the London housing crisis or to empower a candidate to do so will leave Londoners hungry for a better option. This is just the sort of fertile ground in which someone like Russell Brand, or the Green Party could seed a strong mayoral candidacy.

Electoral failure for Labour doesn't depend on an insurgent candidate winning. Labour will know it has lost its London heartlands if it comes third, even if that insurgent candidate only comes second. This would highlight, ward by ward in fact, those areas of London that are willing to vote for what they really want rather than just voting Labour to keep out the Conservatives.

In a fragmenting political landscape Labour still clings desperately to its "least bad potential government" electoral strategy, which has already allowed the SNP, Ukip and the Greens to eat away at their support. With a strategic housing policy that actually addresses the crisis people face, Labour could start to win back enthusiastic supporters. And if they (or the other parties) would like such a policy platform, we're happy to help them develop it.

Alex Hilton is director of Generation Rent. See its rent control campaign here and read its publication on rent control here.