Democratic Senate hopeful John Fetterman is urging his supporters to join him in an effort to get Debbie Wasserman Schultz to resign as chair of the Democratic National Committee.

Fetterman, a Pennsylvania mayor who has endorsed Bernie Sanders for president, is taking Schultz to task over her support for a bill in Congress that he says would gut rules set by the Consumer Financial Protection Bureau designed to protect vulnerable Americans from predatory lenders.

"It's ridiculous that the leader of the Democratic Party would turn her back on some of the most vulnerable members of society—the very people that her candidates are pledging to fight for," Fetterman wrote in an email to his supporters. "That's why today, I'm calling on the Chair to resign. Debbie Wasserman Schultz has made it clear that her values are no longer our values."

Schultz signed on last week as a co-sponsor for a bill that would amend previous legislation that would delay new regulations on payday lenders by two years, arguing that Florida has already taken action against predatory lenders that would be undone by the new CFPB rules.

Her opponents point out, however, that the laws touted by Schultz have done little to protect Floridians from predatory lenders. A study by Pew Charitable Trust found that "a typical Florida payday loan customer ends up taking out nine payday loans a year and is stuck in debt for nearly half of that year," the Huffington Post reported last week.

Fetterman is asking supporters to sign a petition telling Schultz that she has "betrayed" their party's supporters with her support for the bill.

"You have abandoned the values of the Democratic Party and betrayed the most vulnerable members of society who depend on our party to fight for them," says the petition. "I urge you to resign from your position as DNC Chair immediately."

The DNC did not return a request for comment on Fetterman's petition.

This is not the first time Schultz has been asked to resign by a member of the party that hasn't thrown their support behind Hillary Clinton.

Last week Rep. Tulsi Gabbard (D., Hawaii) resigned from her position as vice-chair of the DNC and announced her endorsement of Sanders. She previously voiced her opinion that the party had "punished" candidates who wanted to have more debates.

Fetterman did not respond to an inquiry into whether his support of Sanders played a role in his call for Schultz to resign, but did include praise for Sanders in his email on the issue.

"Thanks to presidential candidates like Bernie Sanders, income inequality is now front and center in the Democratic debate, forcing candidates up and down the ballot to come to the table with plans that level the playing field," wrote Fetterman. "To have the Chair of our Party championing an industry that is preying upon families struggling to get out of poverty is deplorable."