The Bernie Sanders campaign announced on Sunday that it raised $20m in January, almost entirely from small online contributions of $27.

The Vermont senator’s bid for the Democratic presidential nomination has received a record 3.25 million individual contributions, more than any other candidate for the president.

The Sanders campaign raised almost $33.6m in the fourth quarter of 2015, it said, with 70% coming from contributions of $200 or less. Sanders’ campaign has now surpassed the huge funds raised by Barack Obama’s campaign in the first quarter of 2008, before he defeated Hillary Clinton in the primary election.

In a press release, the campaign contrasted Sanders’ small funders with the major backers of Clinton, who led him by three points in the final poll before the Iowa caucuses, a survey released by the Des Moines Register and Bloomberg on Saturday night.

Citing Federal Election Commission reports, the campaign noted that three of every five dollars given to Clinton came from people who have already given her the maximum $2,700.

“As Secretary Clinton holds high-dollar fundraisers with the nation’s financial elite,” campaign manager Jeff Weaver said in a statement, “working Americans chipping in a few dollars each month are not only challenging but beating the greatest fundraising machine ever assembled.”

The campaign also boasted, somewhat disingenuously, that Sanders “has refused to coordinate with a Super Pac”. Technically no candidate is allowed to coordinate with such organizations, which can raise unlimited funds on behalf of a preferred campaign or party.

Super Pacs have ballooned in the wake of the supreme court’s 2010 Citizens United decision, which Sanders decries as evidence of the corrupting influence of money in politics.

Clinton and most of the Republican candidates have Super Pacs acting on their behalf, one of which says it raised $25m for the former secretary of state in 2015, and $50m so far.

Sanders has made Clinton’s complicated relationship with Wall Street a primary if sometimes veiled line of attack on the campaign trail, highlighting the large paychecks she received from banks for speaking.

When the Sanders campaign released its figures on Sunday, Clinton had not yet reported how much money her campaign raised in the fourth quarter of 2015.

This month, the former secretary of state took a break from he campaign trail in Iowa and New Hampshire to attend a fundraiser in Philadelphia, alongside singer Jon Bon Jovi and finance executives. The price of breakfast at the closed press event ranged from $250 to the maximum contribution of $2,700.