Massachusetts Sen. Elizabeth Warren (D), a leading progressive lawmaker and former presidential candidate, will host a high-dollar fundraising event for former Vice President Joe Biden, according to the New York Times.

The move is a departure from Warren's stance on big money in politics. The senator has a reputation for her vocal opposition against billionaires and their influence in government, the economy and public policy. 

The online event is set to take place on June 15 and will feature a network of donors Warren has built from her Senate campaigns.

In the early stages of the the Democratic presidential primary, Warren was one of the candidates, alongside Sen. Bernie Sanders (I-Vt.), who refused to take large sums of money from wealthy donors, touting her campaign as a "grassroots movement." 

“That means no fancy receptions or big money fund-raisers only with people who can write the big checks,” Warren said in an email to supporters at the time, according to the Times.

“It means that wealthy donors won’t be able to purchase better seats or one-on-one time with me at our events. And it means I won’t be doing ‘call time,’ which is when candidates take hours to call wealthy donors to ask for their support.”

Warren has begun aligning herself more with Biden, the presumptive Democratic nominee, who is reportedly scouting Warren among other Democratic women as a potential running mate. 

Politico reported this week that at a University of Chicago Institute of Politics webinar Warren backtracked on her stance on "Medicare for All", suggesting that right now, the government needs to be “strengthening the Affordable Care Act” and “eventually” get to a single-payer system. 

Warren was one of two progressive candidates in the crowded Democratic primary who were in favor of universal health care via the Medicare for All proposal, which Biden is against.