Politicians and campaigners are planning a final push to persuade the government to introduce a universal cap on political donations, warning that last week’s £72m to Reform is the tip of the iceberg.

Labour, the Conservatives and the Liberal Democrats believe the combined sum given by the crypto billionaires Christopher Harborne and Ben Delo may yet fall foul of retrospective changes to residency rules for donations, which feature as part of the Representation of the People Bill currently making its way through Parliament. This requires an individual to have been resident in the UK for a full calendar year before making a donation, and applies retrospectively from March 2026.

However, with the legislation now going through the House…