Former President Donald Trump sued New York Attorney General Letitia James on Monday, seeking to block a long-running civil fraud investigation into his business practices and to bar a criminal investigation.

The complaint was filed in the Northern District of New York after it was reported that James’s office would seek to question Trump as the office investigates whether the Trump Organization manipulated valuations of its real estate properties.

Trump and the Trump Organization, the plaintiffs, alleged that James is using her office’s power to serve her own political interests. Trump’s rights are therefore allegedly being violated. The complaint points to public statements made by James against Trump to argue that James, a Democrat, is motivated by partisan bias against Trump, a Republican.

The complaint states:

Since taking office, she has tirelessly bombarded him, his family and his business, Trump Organization LLC, with unwarranted subpoenas in a bitter crusade to ‘take on’ the President. Her mission is guided solely by political animus and a desire to harass, intimidate, and retaliate against a private citizen who she views as a political opponent.

James’s civil investigation is related to, but separate from, Manhattan District Attorney Cyrus Vance’s criminal investigation of the Trump Organization’s business practice. Vance’s investigation is over three years old and focuses on whether the Trump Organization overstated the value of some real estate assets in order to get loans and tax benefits.

The complaint seeks a court order to prevent the investigation from going forward. “The Trump Organization has continually sought to delay our investigation into its business dealings,” James provided in a statement. “To be clear, neither Mr. Trump nor the Trump Organization get to dictate if and where they will answer for their actions.”