(Reuters) - Former Vice President Joe Biden on Thursday appeared to soften his stance against taking campaign contributions from super PACs, high-dollar groups that his rivals for the Democratic Party’s presidential nomination have sworn off.

FILE PHOTO: U.S. Democratic presidential candidate and former U.S. Vice President Joe Biden speaks during a forum held by gun safety organizations the Giffords group and March For Our Lives in Las Vegas, Nevada, U.S. October 2, 2019. REUTERS/Steve Marcus/File Photo/File Photo

“In this time of crisis in our politics, it is not surprising that those who are dedicated to defeating (President) Donald Trump are organizing in every way permitted by current law to bring an end to his disastrous presidency,” Biden spokeswoman Kate Bedingfield said in an oblique reference to campaign finance regulations.

The statement, which was immediately criticized by activists seeking to lessen the influence of so-called dark money in politics, came as the Democratic frontrunner struggles with slow fundraising and a barrage of attack ads from the campaign of Trump, the likely Republican nominee.

Trump and his allies “are already spending massive amount of money on paid television and digital advertising to intervene directly in Democratic primaries with the goal of preventing Joe Biden, the opponent that Trump fears most, from becoming the Democratic nominee,” Bedingfield said.

Biden raised $15.2 million to support his U.S. presidential bid during the third quarter, trailing some of his rivals, and had just under $9 million left in his coffers after expenditures.

The former vice president has had less luck than rivals Bernie Sanders and Elizabeth Warren in raising money from small-dollar individual donors. Biden had earlier joined them and other candidates in swearing off donations during the primary season from corporate PACs or independent committees.

Biden has said that he feels confident that he is raising enough money to run his campaign. His campaign on Thursday did not answer a question from Reuters about whether Biden would now accept super PAC help, instead releasing the statement from Bedingfield.

Tiffany Muller, president of the campaign finance reform group End Citizens United, unleashed a volley of criticism at Biden on Twitter, and in a statement sent to reporters.

“@StopBigMoney is calling on @JoeBiden to reconsider this decision and disavow single-candidate Super PACS supporting his candidacy,” Muller wrote.

“Last month, @JoeBiden said he wouldn’t embrace a single-candidate Super PAC,” Muller added. “Today, he broke that promise.”

Biden announced his candidacy in April, later than some rivals. The campaign has also abstained from accepting cash from federally registered lobbyists and certain corporate fundraising entities that are allowed raise unlimited sums of money.

Trump, who has not sworn off super PAC donations, and his party jointly raised $125 million for his 2020 reelection bid in the third quarter, the Republican National Committee said.

After a whistleblower complaint prompted Democrats to open an impeachment inquiry into whether Trump illegally asked Ukraine to investigate Biden and his son, Hunter, the Republican has repeatedly criticized Biden.

Trump’s reelection campaign has also released ads targeting Biden and his son.