(CNN) Bernie Sanders on Wednesday hammered Hillary Clinton's super PAC's fundraising haul, playing up his $3.5 million in individual contributions following the Iowa caucuses.
The Vermont senator called Clinton part of "establishment politics and establishment economics" in an interview with CNN's Wolf Blitzer.
He pointed to Clinton's Priorities USA Action, which reported raising $25.3 million in the second half of 2015 -- including, Sanders said, $15 million attached to Wall Street interests.
"That is a very significant difference," he said. "Our campaign is funded by the people. To a significant degree, her campaign is funded by Wall Street and big money interests."
Sanders also questioned Clinton's assertion that she is progressive, pointing to the months she waited before announcing her opposition to the Trans-Pacific Partnership trade deal and the Keystone XL pipeline.
"Most progressives that I know really do not raise millions of dollars from Wall Street," Sanders said. "Most progressives that I know are firm from day one in opposition to the Trans-Pacific Partnership, the TPP agreement. They didn't have to think about it a lot. They were opposed to Keystone from day one, they didn't have to vacillate on that issue."
His comments came the day after Sanders said Clinton is progressive on "some days."
Clinton hit Sanders for that comment on Wednesday.
"We've been fighting the progressive fight and getting results for people for years," Clinton said at a town hall event. "So I hope we keep it on the issues, because if it's about our records, hey, I'm going to win by a landslide."