Sen. Bernie Sanders Bernie SandersSirota reacts to report of harassment, doxing by Harris supporters Republicans not immune to the malady that hobbled Democrats The Hill's Morning Report - Sponsored by Facebook - Republicans lawmakers rebuke Trump on election MORE's (I-Vt.) campaign is hitting former Vice President Joe Biden Joe BidenFormer Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick Bloomberg rolls out M ad buy to boost Biden in Florida MORE over what Sanders is calling a “reversal” on accepting donations from super PACs.

The campaign accuses Biden's team of flipping on the matter after lagging behind Sanders in bringing in small donor funds.

“The former Vice President has been unable to generate grassroots support, and now his campaign is endorsing an effort to buy the primary through a super PAC that can rake in unlimited cash from billionaires and corporations,” Sanders's campaign manager Faiz Shakir said in a statement. ADVERTISEMENT

“That’s not how we defeat Trump. It’s a recipe to maintain a corrupt political system which enriches wealthy donors and leaves the working class behind.”

Biden’s campaign signaled it would accept such donations Thursday in a statement to NBC News.

Deputy campaign manager Kate Bedingfield doubled down on Biden’s commitment to “remove private money from our federal elections” if elected. But she indicated the Biden campaign would be open to accepting such donations in the 2020 election.

“Until we have these badly needed reforms, we will see more than a billion dollars in spending by Trump and his allies to re-elect this corrupt president. And let's be clear: Donald Trump Donald John TrumpFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Former Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick MORE has decided that the general election has already begun,” she said.

"In this time of crisis in our politics, it is not surprising that those who are dedicated to defeating Donald Trump are organizing in every way permitted by current law to bring an end to his disastrous presidency," Bedingfield continued. "Nothing changes unless we defeat Donald Trump."

The Biden campaign did not immediately return a request for comment.

Biden had previously disavowed support from an outside super PAC.

Sanders raised the most money out of candidates in the crowded field at the end of last quarter, bringing in $25.3 million. Sen. Elizabeth Warren Elizabeth WarrenOvernight Defense: Appeals court revives House lawsuit against military funding for border wall | Dems push for limits on transferring military gear to police | Lawmakers ask for IG probe into Pentagon's use of COVID-19 funds On The Money: Half of states deplete funds for Trump's 0 unemployment expansion | EU appealing ruling in Apple tax case | House Democrats include more aid for airlines in coronavirus package Warren, Khanna request IG investigation into Pentagon's use of coronavirus funds MORE (D-Mass.) came in at a close second at $24.6 million.

Biden reported bringing in $15.2 million, placing him fourth in terms of most funds raised behind South Bend, Ind., Mayor Pete Buttigieg Pete ButtigiegBillionaire who donated to Trump in 2016 donates to Biden The Hill's Morning Report - Sponsored by Facebook - GOP closes ranks to fill SCOTUS vacancy by November Buttigieg stands in as Pence for Harris's debate practice MORE who brought in $19.2 million.