Nearly 100 Labour MPs are supporting an amendment calling for a national commission on replacing first past the post with a different electoral system. The proposal would require the commission to report before the next general election, potentially allowing Labour to include reform in a future manifesto; supporters argue the current system does not reflect overall vote shares.

The amendment to the Representation of the People Bill has backing from more than 180 MPs, including 98 Labour MPs, and is due to return to Parliament on 2 September. Andy Burnham has previously endorsed proportional representation, but a Labour source said the government is currently focused on manifesto commitments such as votes at 16 and tighter donation rules, while electoral reform would require a future mandate. Opponents cited the 2011 referendum, in which voters rejected the alternative vote system, and argued the government should prioritise other issues.