D.C. Mayor Muriel Bowser violated District law late this summer when she created a new office to manage the city’s art collection and public art, according to the D.C. Attorney General’s office.

Bowser established the Creative Affairs Office in August amid a months-long power struggle with the D.C. Council over who will control the city’s arts infrastructure, including grant funding, public art projects and city-sponsored cultural events.

On Monday, Deputy Attorney General Brian Flowers issued a memorandum stating that the office, led by Bowser, does not have the right to control the city’s works of art and public art. D.C. law already grants that power to another city agency, the Commission on Arts and Humanities.

The memo also states that the Mayor “no longer has day to day supervisory authority over the [Commission on Arts and Humanities] functions.”

A bit of context: The Attorney General’s office wrote the memo after D.C. Council Chairman Phil Mendelson requested a review of the legal structures of the arts commission and the Creative Affairs Office. Mendelson and Bowser have been sparring for months over the arts office.

This year, the D.C. Council voted to make the arts commission into an independent agency. Bowser still can appoint and remove its board members, but the office is no longer headed by a mayoral appointee.

Then, during the agency’s transition in late August, Bowser established a new Creative Affairs Office. Its director will report to Angie Gates, a longtime Bowser supporter and the head of the Office of Cable Television, Film, Music and Entertainment.

Meanwhile, the mayor’s office, D.C. Council members, and arts commission staff continued to duke it out over who controlled what at the agency.

In September, the Washington City Paper reported that Bowser’s office locked arts commission staff out of the Art Bank, the agency’s vault of city-owned public art. The arts commission’s board chair directed staff to suspend all major business for a week until the agency became officially independent, prompting a series of angry phone calls between her and Deputy Mayor John Falcicchio, as well as between Mendelson and Bowser herself.

The resulting memo is a win for Mendelson, as it directly curtails Bowser’s ability to exercise authority over the arts commission’s functions.

“It is beyond the scope of the Mayor’s authority,” the memo reads, “to continue to exercise control of the Art Bank or interpose other executive branch officials to supervise or regulate the exercise of [the art commission’s] functions.” The memo states that the commission should retain control of the Art Bank.

“We are on solid legal ground,” the Executive Office of the Mayor said in a statement to WAMU. “Residents and visitors can enjoy the art on display at government agencies and buildings, and they will continue to be able to do so.”

Mendelson called the response “false and inaccurate” in a phone call with WAMU. “They made their best case as to why they have authority, and they don’t. They just don’t,” he said. “I would hope that the mayor would follow the law.”

A spokesperson for the arts commission did not respond to a request for comment by publication time.

At stake in the midst of this tug-of-war is the support of the city’s creative constituency: The cultural industry is responsible for more than 150,000 jobs and $12.4 billion in wages, according to the D.C. Cultural Plan. D.C. artists and leaders of arts organizations are watching the debate closely, in large part due to their reliance on the city’s purse for funding. In fiscal year 2017, the arts commission allocated some $23 million in arts grants, which are the lifeblood of many arts nonprofits and up-and-coming artists.

This story first appeared on WAMU.