Nigel Farage’s insurgent Reform U.K. party has attracted more than a dozen donors from Britain’s once dominant Conservative Party, new data reveals, underlining the threat the Tories face from a right-wing populist party that models itself on President Trump’s MAGA movement.

In total, Reform U.K. raised 4.75 million pounds ($6.1 million) last year, a sharp increase from the less than $200,000 that the party raised in 2023. A third of the money came from former donors to the Conservatives.

The New York Times analyzed every donation that Reform U.K. reported to Britain’s campaign finance watchdog in 2024, including figures for the final quarter of the year that were released on Thursday, to get the first major snapshot of who is funding the party.

The biggest single donation in the last quarter came from Roger Nagioff, a former Conservative donor, former Lehman Brothers banker and Monaco-based investor, who donated £100,000 in December. Other major donations in 2024 included one million pounds from a company owned by Reform’s deputy leader, Richard Tice, and £500,000 from Fiona Cottrell.

The Conservative exodus began after Mr. Farage, an ideological ally of Mr. Trump, took over last year as Reform’s leader just before Britain’s July general election. A longtime political disrupter and former commodities trader who campaigned for Brexit, Mr. Farage has pledged to remake British conservatism, pushing the movement to the right on a nationalistic platform that he frames as anti-establishment and anti-immigration.

Reform has surged in national polls, overtaking the Conservative Party, and taken its first municipal seats. Although the governing Labour Party does not have to hold a general election until 2029, Reform’s fund-raising success underlines Mr. Farage’s momentum and could help his party professionalize as it challenges the two main parties at local elections in May.

While Mr. Farage has described support for Reform as a “revolt against the establishment,” 34 percent of the party’s new funders are former donors to the Conservatives, the centuries-old right-wing party that held power for 14 years in Britain before last year’s general election.

Sam Power, a political finance expert at Bristol University, said that the latest data was a stark warning to the Conservative Party, which is led by Kemi Badenoch.

“The movement of donors from the Conservative Party to Reform already I think will be causing alarm bells in Conservative Party HQ,” Mr. Power said.

“Money talks, and what you can see, if money is moving from one party to another, then that is a major sign that the sands are shifting,” he said. “Not just in terms of elections and the public being Reform-curious, but that donors are increasingly Reform curious, too.”

Other major donors bankrolling Reform in 2024 included billionaires and millionaires, individuals based in overseas jurisdictions or with offshore investments, climate change skeptics and those with investments in fossil fuels or other climate-polluting industries, The Times found.

Reform, which Mr. Farage originally created in 2019 as the Brexit Party, won 14.3 percent of the vote in last year’s general election. But in recent weeks, it has reached around 25 percent in several polls, at times overtaking the Conservatives and Labour.

This is a developing story. Please check back for updates.