British politics is increasingly being funded by individual billionaires with a wave of mega-donations having flooded into UK political parties over the past two parliaments.
A total £179m has been donated by wealthy individuals since 2019, research reveals.
The figures from the IPPR thinktank show how big money is playing an ever more influential role in Westminster, with a particular rise in mega-donations of more than £1m.
The research found that contributions from individual donors has accelerated since the Brexit party got £10m from the Thailand-based billionaire Christopher Harborne and the Liberal Democrats were given £8m by David Sainsbury, the supermarket tycoon, who has now returned to Labour.
Between 2001, when donation records began, and 2018, the total donated by individuals giving more than £1m averaged £3.9m a year.
But between 2019 and 2025, that figure rose to £13.1m a year, almost three-and-a-half times as much, and far outstripping what would be expected with inflation.
The research found 72% of all £1m-plus donations from individuals since records began had come since 2019.
Guardian analysis found that in some years, such as 2023, almost £7 out of every £10 in reported private donations to political parties came from wealthy companies or individuals who gave more than £1m in a calendar year.
The figures are likely to raise fresh concerns about the influence of a small groups of wealthy individuals, which have already been heightened since two crypto billionaires, Harborne and Ben Delo, said they had each given £36m to Reform UK this month.
Reform UK has said it is trying to redress the balance as the other parties have taken millions in mega-donations in past years. The Conservatives’ biggest donors include Frank Hester, who gave more than £20m before the 2024 election, and Labour’s Gary Lubner who has given more than £9m in total.
The IPPR figures draw on Electoral Commission data since 2001 and Transparency International analysis, plus the two record donations of £36m each to Reform UK from Harborne and Delo.
There is increasing concern among Reform UK’s rivals about the issue of donations of more than £1m, with some Labour MPs pushing for a cap of £100,000 or £500,000 a year.
Some Labour members are intending to push the issue at the party’s autumn conference, and proposals for a cap are likely to be tabled when the government’s current elections bill goes to the House of Lords this autumn.
No 10 has been reluctant to include a cap amid opposition from some trade unions who fear it could lead to restrictions on them being able to donate so much in future.
However, the government has recently pledged to deal with the issue of mega-donors having an outsize influence on politics. It has already brought in a cap of £100,000 a year for donations from overseas voters.
Harry Quilter-Pinner, the executive director of IPPR, said: “Something fundamental has changed in how British politics is funded. Million-pound donations were once exceptional. However, since 2019, mega-donor money has become a much bigger part of our political system.
“Reform’s extraordinary fundraising has accelerated that trend, but this is much bigger than one party or two enormous cheques. This is the Americanisation of British politics, where political parties can become dependent on a handful of people with exceptionally deep pockets.
“Britain should draw a clear line. The government should introduce a £100,000 annual cap now and bring it down over time, so that no individual can bankroll a political party simply because they are incredibly wealthy.”
Civil society groups have urged the government to fix the issue for good, after the government said earlier this month a new taskforce would examine the issue of mega-donations.
Dr Susan Hawley, executive director of Spotlight on Corruption, said: “Without urgent action to limit the amount that wealthy individuals can give to political parties, we’re going to continue to see a staggering inflation of money – and the influence it buys – flowing into the coffers of political parties … The taskforce needs to take decisive action to get big money out of our politics in a fair and even-handed way, so that power and influence is returned to ordinary voters, where it belongs.”
At the time of the £72m in donations to Reform UK, Duncan Hames, senior director of policy at Transparency International UK, said the situation with big donations was “completely out of control, and makes an irrefutable case for government to bring forward an annual cap on political donations, and fast.”
