Sen. Elizabeth Warren, D-Mass., fired off a scathing 13-page open letter to the head of the Securities and Exchange Commission, criticizing her for a "failure" to keep promises made in confirmation.

Warren put Mary Jo White in the crosshairs of an unusually acidic criticism, saying her leadership is “extremely disappointing” and alleging that the SEC director provides “misleading information.”

The Boston Globe has coverage.

In the 13-page letter, Warren said there has been a “significant gap” between the promises White made during her confirmation and her subsequent performance helming the independent commission.

“I am disappointed that you have not been the strong leader that many hoped for — and that you promised to be,” Warren wrote in the letter sent Tuesday. “I hope you will step up to the job for which you have been confirmed.”

It is Warren’s latest public fight against an official who is backed by her own party and the clearest sign to date of a rift opening between the SEC and the liberal wing of the Democratic Party. Warren’s battle cries tend to set the agenda for the left and are igniting passion from her hundreds of thousands of followers across the country.

White defended her tenure at the SEC in a statement Tuesday morning. “I am very proud of the agency’s achievements under my leadership, including our record year in enforcement and the commission’s efforts,” White said.