Baltimore Mayor Catherine Pugh, who last week took an indefinite leave of absence from office amid an ongoing book controversy, has been called to step down immediately by the city council.

The 14 members of the Baltimore City Council sent a two-sentence letter to Pugh on Monday urging her to resign, effective immediately. All members of the city council except acting mayor Bernard C. "Jack" Young signed the letter.

“The entire membership of the Baltimore City Council believes that it is not in the best interest of the City of Baltimore for you to continue to serve as Mayor,” the council members wrote to Pugh. “We urge you to tender your resignation, effective immediately.”

BALTIMORE MAYOR'S $500G DEAL FOR 'HEALTHY HOLLY' CHILDREN'S BOOKS DRAWS SCRUTINY

Copies of the letter were also sent to City Solicitor Andre Davis, Pugh’s chief of staff Bruce Williams, the city’s senators and delegates in the Maryland General Assembly and Young.

Pugh is under fire after she reportedly received $500,000 from the University of Maryland Medical System for her self-authored “Healthy Holly,” a children’s book series.

The university paid Pugh for 100,000 copies of her books between 2011 and 2018 while she was on its board. The books were intended to go to schools and day care centers, however, some 50,000 copies remain unaccounted for and may never have been printed, the Baltimore Sun reported.

BALTIMORE MAYOR CATHERINE PUGH TAKES INDEFINITE LEAVE OF ABSENCE AMID BOOK CONTROVERSY

The state prosecutor opened an investigation earlier this month into the books’ sales, the Baltimore Sun reported.

Pugh announced last Monday she was taking an indefinite leave of absence to recover from a bout of pneumonia for which she was hospitalized for five days. Her spokesman told the Baltimore Sun on Saturday that Pugh intends to return to her post once her health has sufficiently improved.

This statement appeared to prompt the City Council to urge her to step down.

“Baltimore will continue to have a cloud over its head while the investigations into Mayor Pugh’s business dealings go on,” Councilman Brandon Scott said in a statement. “My colleagues and I understand the severity of the action we have taken, but know that it’s what’s the best for Baltimore.”

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Councilman Zeke Cohen said while the move was “unprecedented,” it is the best course for Baltimore.

Pugh, at a news conference last week, described the book deal with the university-based health care system as a "regrettable mistake," and apologized for "any lack of confidence or disappointment" citizens and colleagues may have felt.

Pugh has not commented on the city council’s letter.

Fox News' Nicole Darrah contributed to this report.