Sen. Elizabeth Warren, D-Mass. (AP Photo/Cliff Owen, File)

Sen. Elizabeth Warren delivered influential support Monday for Hillary Clinton's proposal to expand regulation of the banking and financial services industries.

Warren said she welcomes Clinton’s warning that Republicans are trying to use the current government spending bill to weaken regulations. The liberal Massachusetts Democrat has declined to endorse anyone in the Democratic presidential primary so far.

Clinton wrote an op-ed piece that appeared Monday in the New York Times that calls on Congress not to strip funding for the watchdog Consumer Financial Protection Bureau.

“Secretary Clinton is right to fight back against Republicans trying to sneak Wall Street giveaways into the must-pass government funding bill,” Warren wrote on Facebook.

Warren, an anti-Wall Street crusader who disappointed many very liberal Democrats by refusing entreaties to run for the 2016 nomination, previously oversaw the CFPB.

She wants to go farther than Clinton in breaking up big banks, but outlined with approval the areas where their proposals align.

“Whether it’s attacking the C.F.P.B., undermining new rules to rein in unscrupulous retirement advisers, or rolling back any part of the hard-fought progress we’ve made on financial reform, she and I agree,” Warren wrote.

Warren was the lone holdout among women Democratic senators who publicly endorsed Clinton as a Washington fund-raiser last week. Warren has not said when or if she will endorse anyone.

But her support for Clinton’s platform is notable because rivals Sen. Bernie Sanders and former Maryland governor Martin O’Malley both support reinstating the old Glass-Steagall Act rules that would force bank breakups, a position closer to Warren’s.

"Republicans, both in Congress and on the campaign trail, are dead-set on rolling back critical financial protections," that are part of the Dodd-Frank legislations passed after the 208 financial crisis, Clinton wrote in the Times piece.

"President Obama and congressional Democrats should do everything they can to stop these efforts," Clinton wrote, adding that if elected she would seek "tough new rules, stronger enforcement and more accountability.”

Warren has also recently praised Sanders, an independent senator from Vermont and the primary beneficiary of her own decision not to run. She has said it is not the right time for her to endorse anyone.

“Bernie is doing what Bernie always does,” Warren said in an interview Saturday with the Boston Herald. “He’s out there talking from the heart, raising the issues that he’s raised for decades now.”