Washington’s police department chief says a Trump administration order installing a federal official as its head would upend command structure and be a “dangerous” threat to law and order.

DC Attorney General Brian Schwalb filed a lawsuit Friday against the Trump administration over its moves to take over the city’s police department and appoint an emergency commissioner, the latest sign of pushback from district officials against the federal takeover.

The Washington, D.C., attorney general sued the Trump administration Friday, alleging the president has overstepped his authority in a takeover of the Metropolitan Police Department—legal action that comes a day after the Trump administration attempted to effectively replace D.C.’s police commissioner with a federal official.