Newark Mayor Luis Quintana has made a lot of moves since taking the helm of the state’s largest city from Cory Booker.

MORE: But What Did Cory Booker Actually Accomplish in Newark?

He fired a host of Booker loyalists before Thanksgiving and tried to install his own team in City Hall while he serves out Booker’s term.

But change comes hard in Newark, especially when the city is operating under a state monitor.

Local Government Services director Thomas Neff issued a stern warning to Quintana Wednesday, reminding him that according to a memorandum of understanding between Newark and the state, Quintana needs state approval for any new hires, according to a letter obtained by The Star-Ledger.

Even without that memorandum, Quintana may have run afoul of state statute by firing his finance director, Susan Jacobucci, Neff said.

"The purpose of this letter is to provide you with notice of potential violations of State law associated with certain recent proposed personnel actions by the City of Newark," Neff wrote in the letter to Quintana. "If these actions have been accurately reported in press accounts, we would require that they be immediately addressed."

Quintana took over as mayor when Booker was elected to the U.S. Senate in October. Last week, The Star-Ledger reported that he was hiring former councilman Hector Corchado as a deputy police director, Rahaman Muhammad as a director of operations, Esmeralda Diaz Cameron as director of communications, along with a spate of others to fill out his new administration.

Since Newark took $32 million in emergency state aid in 2011 and 2012, though, the city has to get state approval for any new hires. Neff wrote that in the interest of maintaining a "working relationship" with Newark, the city needs to get approvals from his office before anyone can collect a paycheck.