U.S. Sen. Elizabeth Warren is urging America’s financial powerhouses to lobby the incoming Trump administration to keep the Department of Labor’s fiduciary rule on time and intact.

“I think we can agree that the very least we should do [to ease the retirement crisis] is ensure investment advisor fees, commissions and kickbacks aren't draining away the money Americans do manage to save. DOL's rule does just that,” said Warren in a letter to 33 of the nation’s largest banks, asset management companies, broker-dealers, financial advisory firms and insurers.

Among the recipients: Vanguard Group, Charles Schwab, TD Ameritrade, TIAA and LPL Financial. Most of these companies have already embraced and supported the DOL's fiduciary rule.

The letter came out Thursday as the Democratic liberal leader said she has seen reports that as early as Monday Trump may seek to substantially delay the rule scheduled to start taking effect in April.

“I am troubled by the news that one of the incoming administration's first orders of business will be to try to delay this common-sense consumer protection,” wrote the senator.

She said rolling back the regulation, which says that pension fund advisors must work in the best interests of participants, would undermine Americans’ newfound confidence in their investment advisors and may lead to immediate price increases and the return of dangerous commission-based sales incentives that benefit advisors' bottom lines but drain away consumers' savings.

In addition, Warren cautioned that a rollback would disadvantage “honest and hardworking” investment advisors and broker-dealers who, without the rule, would no longer be competing on a level playing field.