More in Common has modelled three proportional representation systems against current UK polling for the Guardian, and the headline finding is stark: no system — including the current one — gives any party a majority. But the distribution of power shifts dramatically depending on which counting method you use. Under first past the post, Labour converts 26% of the vote into 39% of seats — a distortion ratio of 1.5x that has been the defining feature of British elections for decades. All three PR systems (regional party list, STV, additional member system) compress that ratio close to 1:1, giving Labour between 26% and 27% of seats. The winners are not centrist parties but those at the margins: the Greens leap from 3 seats under FPTP to more than 50 under any PR model, and Restore Britain surges from 1 seat to over 30. This is the central tension the modelling exposes. PR's promise is representational fairness — seats matching votes. Its mechanical consequence is fragmentation. With Labour, Reform, and the Conservatives clustered within six points of each other (26%, 23%, 20%), even small vote shifts under FPTP produce volatile seat swings. Under PR, those shifts are dampened, but the price is permanent coalition politics where fringe parties hold kingmaker roles. The regional distortions are equally revealing. Labour currently holds 69% of London's seats under FPTP on far less than 69% of the vote. Under party list PR, that drops to 37%, with Reform and the Greens collectively picking up nearly a quarter of the capital's seats. In the east of England, Reform's 43% FPTP seat share falls to 29% under PR. The geographic fiefdom model of British politics — Labour owns cities, Conservatives own shires — would fracture. Prime Minister Andy Burnham has announced a national commission on electoral reform, backed by over 100 Labour MPs and supported by the Liberal Democrats, Greens, SNP, and Plaid Cymru. His conference speech framed it as preventing a "divisive government" winning on sub-30% vote share. The 2011 AV referendum, which decisively rejected a much milder reform, looms as the obvious precedent for why this may stall. More in Common's Charlie Buckley put the structural problem plainly: the real PR winners are "on the edges of the political spectrum," and the prospect of forming a workable majority "looks even more complicated under a proportional one." Notably, when the same team ran this modelling in July with Reform leading the polls, PR equally denied Reform the FPTP seat bonus. The system punishes whoever is leading. The deeper question is whether Britain's political class — and its voters — can tolerate what PR actually produces: not fairness in the abstract, but coalition governments where Restore Britain or the Greens can extract policy concessions far beyond their vote share as the price of participation. Electoral reform is being sold as democratic hygiene. The modelling shows it is a power redistribution with winners and losers that neither side of the debate is being fully honest about.
