A new court filing from the Trump family accuses New York Attorney General Letitia James of abandoning legal principals in an attempt to gain political support as she continues a three-year investigation into the family’s business practices.

The complaint, which was filed Tuesday by attorneys for former President Trump and two of his children, Donald Trump Jr. and Ivanka Trump, alleges that James has "repeatedly threatened investigation and prosecution" of the Trump family to "garner votes, money and support, and now, as Attorney General, to gain political support."

Donald Trump Jr. and Ivanka Trump

Donald Trump Jr. and Ivanka Trump (AP Photo/John Locher)

DONALD TRUMP JR., IVANKA TRUMP SUBPOENAED BY NY ATTORNEY GENERAL IN TRUMP ORGANIZATION PROBE

James recently issued subpoenas for Donald Trump, Ivanka Trump and Donald Trump Jr. in connection with an ongoing civil investigation. Those subpoenas sought testimony and documents "in connection with an investigation into the valuation of properties owned or controlled by Donald J. Trump or the Trump Organization, or any matter which the Attorney General deems pertinent thereto."

A preliminary statement included in the filing, which alleged James sidestepped the state constitution, claimed the office of New York's attorney general (OAG) "runs from the words of Letitia James, deliberately avoiding the fact that she has taken equal ownership of the current criminal case and the ongoing grand jury investigation" targeting the Trump family.

The complaint targets James for her "blatant and obvious attempt to suppress [Donald Trump's] voice, interfere with his political ambitions and silence the will of millions of voters" over the last three years, as well as her efforts to collude with former New York County District Attorney Cyrus Vance Jr. to run parallel investigations.

New York Attorney General Letitia James addresses a news conference at her office in New York, May 21, 2021.

New York Attorney General Letitia James addresses a news conference at her office in New York, May 21, 2021. (AP Photo/Richard Drew)

A series of arguments presented in the filing accuses New York's chief law enforcement officer of having violated Criminal Procedural Law (CPL) 190.40 and the New York constitution when issuing the Trump family subpoenas.

"The New York Constitution, as interpreted by the Court of Appeals, and the CPL promulgated thereunder, created protections for subpoenaed witnesses that federal law does not provide," the filing stated. "Under the New York Constitution and the CPL, an agency conducting a criminal investigation through an active grand jury is required, if the witness is subpoenaed, to examine the subject or target of the investigation before the grand jury."

The filing concludes James' "investigation and prosecution [is] based solely on political animus" and that "such selective prosecution violates the Equal Protection Clauses of the Federal and New York States Constitutions and requires that the subpoenas be quashed."

President Trump walks across the tarmac to board Air Force One at Andrews Air Force Base Dec. 12, 2020.

President Trump walks across the tarmac to board Air Force One at Andrews Air Force Base Dec. 12, 2020. (AP Photo/Andrew Harnik)

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Donald Trump had sued James in December, seeking to end the investigation after she requested that he sit for a Jan. 7 deposition. That lawsuit, filed in federal court, alleges that the probe has violated his constitutional rights in a "thinly-veiled effort to publicly malign Trump and his associates."

Donald Trump's son Eric Trump, who serves as the executive vice president of the Trump Organization, was already questioned by James’ office in October 2020, the New York Times reported. James’ office went to court to enforce a subpoena on the younger Trump, and a judge forced him to testify after his lawyers abruptly canceled a previously scheduled deposition, according to The Associated Press. 

Fox News' Danielle Wallace and Marta Dhanis contributed to this article.