Donald Trump has raised $75mn less for his presidential bid than Joe Biden and has 270,000 fewer unique donors now than at the same stage of his run for the White House four years ago.

The findings, from a Financial Times analysis of federal campaign data, raise new questions about how the former president's shrunken base will sustain him through costly court cases and what is expected to be the most expensive presidential race ever.

The Trump campaign and affiliated political action committees have attracted roughly 900,000 donors from July 2023 through the first quarter of 2024, compared with 1.17mn donors in the equivalent period of the 2020 race, according to the FT's analysis of federal data.

President Biden has also opened up a massive fundraising advantage, the data shows, raising $165mn over the first three months of the year — $75mn more than pro-Trump groups, which raised just under $90mn.

Biden had $146mn on hand at the end of March and has raised $368mn in this election cycle. Pro-Trump groups must provide numbers by a federal deadline last Saturday night. They had $65mn cash on hand at the end of 2023.

The findings come as both candidates step up their fundraising efforts with just under seven months to go before the November vote.

"President Trump raised more in Q1 when he was the incumbent president than Joe Biden has raised in Q1 as the incumbent president this year,” said Trump campaign spokesperson Karoline Leavitt. "Team Trump will continue to raise the resources necessary to win on November 5th.”

Money remains crucial in the months-long White House races, as candidates blitz swing states with multimillion-dollar ad campaigns before the vote. In 2020, Biden raised a record $1bn in donations, and Trump hauled in about $775mn, according to the non-profit Open Secrets.

Texas businessman Roy Bailey, a top fundraiser for Ron DeSantis's failed presidential campaign, said Biden enjoyed a "huge advantage” as president — but wall-to-wall media coverage of Trump meant he did not need to raise as much money.

"I do think he can make it up,” said Bailey, who fundraised for Trump in 2020 and will again in 2024. "I don't think he needs to, to win the election . . . He'll have the last seven months of the year to put the pedal to the metal.”

Small donors — those giving $200 or less — have been critical to Trump's campaigns. But many megadonors are also now backing him after previously pouring money into Republican primary rivals such as Nikki Haley, who dropped out of the race for the party's nomination last month.

The first-quarter figures do not include some of the recent fundraisers Trump has held with these big-money donors. On April 6, hedge fund billionaire John Paulson hosted an event that the Trump campaign claimed raised $50mn, which would be the biggest political fundraiser in US history. Earlier that week, Biden said he raised more than $25mn at an event with former presidents Bill Clinton and Barack Obama at New York's Radio City Music Hall.

Shale oil baron Harold Hamm, who co-chaired the Paulson fundraiser, told the FT the Florida fundraiser showed Trump was in "very, very good shape” in terms of his fundraising.

"With the amount of money that he raised [at the Florida fundraiser] doubling what Biden had raised even with the help of Obama and Clinton — I think that tells everything that you need to know.”

Trump has used his legal problems to raise money, but is also spending heavily on his defence in four criminal trials and a civil fraud case that threatens his business empire. He was in court in New York again on Tuesday for a criminal trial relating to his payments to a porn star.

This year, Trump has put together $175mn to post bond and appeal a New York civil court case, and sold $399 sneakers and $59.99 Bibles.

Trump will also be able to raise potentially hundreds of millions of dollars selling shares in his recently listed media company as soon as September, just weeks ahead of the election. The stock's value, however, has dropped by two-thirds since its peak three weeks ago.

Pro-Trump groups spent more than $50mn on his legal fees last year. But the former president's best fundraising day among small-dollar donors came on August 25, after he surrendered to authorities in Atlanta on felony charges that he sought to overturn the 2020 election.

Just after he surrendered, Trump's campaign released his mugshot on T-shirts and mugs, drawing in about 85,000 contributions — about 10 times more than a typical day — to bring in almost $4.3mn.

Additional reporting by Jamie Smyth in New York