• House Republican Conference Chair Rep. Elise Stefanik has filed a complaint calling for the removal of the judge presiding over the $250 million business fraud trial of former President Donald Trump.
• Stefanik claimed that Manhattan Supreme Court Judge Arthur Engoron has shown "clear judicial bias" against Trump.
• Engoron is presiding over New York Attorney General Letitia James' case accusing Trump, his two adult sons and others of fraudulently inflating their asset values for various financial benefits.

House Republican Conference Chair Rep. Elise Stefanik on Friday filed an ethics complaint calling for the removal of a judge presiding over the $250 million business fraud trial of former President Donald Trump.

The No. 3 House Republican and one of Trump's most loyal allies in the chamber, Stefanik claimed in her complaint that Manhattan Supreme Court Judge Arthur Engoron had shown "clear judicial bias" against the former president and displayed "bizarre behavior" during his high-profile civil trial.

Stefanik, whose congressional district covers northeast New York, urged the state's Commission on Judicial Conduct to "take corrective action to restore a just process and protect our constitutional rights."

Stefanik also wrote that Engoron "must recuse from this case," although the commission does not have the authority to remove specific judges.

The complaint is a remarkable step by Trump's political allies in Washington to join his aggressive efforts to undermine Engoron, whose rulings in the case could strike a major blow to the ex-president and his business empire.

The letter from Stefanik, who is not a lawyer and has no relation to the case, could also be meant to support Trump's argument if he appeals any of Engoron's eventual rulings.

It comes after a week of testimony in the trial by members of the Trump family that some legal experts say did little to help their case.

The case will settle claims brought by New York Attorney General Letitia James, who accuses Trump, his two adult sons, his company and some of its top executives of fraudulently inflating the values of Trump's assets to boost his net worth and rake in financial benefits.

Engoron will deliver verdicts in the no-jury trial, because neither side requested one.

Engoron has already found the defendants liable for fraud. The trial itself will determine how much the defendants will be ordered to pay in damages or other penalties. The judge will also evaluate six other claims in James' lawsuit that have yet to be resolved.

In addition to seeking around $250 million in damages, James wants to permanently bar Trump Sr., Donald Trump Jr. and Eric Trump from running a New York business.

Stefanik's letter Friday echoed many of Trump's own criticisms of Engoron and James' case as she urged the commission to sanction the judge.

She railed against the judge for striking a pose at cameras in the courtroom on the first day of the trial, for granting James' request for partial summary judgement in a pretrial ruling, and for imposing a gag order on Trump and his attorneys. She also repeated Trump's claim that the value of his Palm Beach, Florida, resort home Mar-a-Lago is much higher than the estimates provided during the trial.

Engoron had barred Trump from making public statements after Trump repeatedly targeted the judge's principal law clerk on the second day of the trial. The judge later extended that gag order to Trump's lawyers after their "repeated, inappropriate remarks" about the clerk.

Trump has been found to have violated that narrow gag order twice since it was imposed, leading to $15,000 in fines. Stefanik called the gag order "un-American."

Her letter also targets the clerk, claiming that she has given more in political donations to Democratic candidates than she is allowed to as a court official.

"Judge Engoron's bizarre and biased behavior is making New York's judicial system a laughingstock," Stefanik wrote. "The Commission's sanctions against Judge Engoron are necessary to bring back credibility to our great state's legal system."

Asked for comment on Stefanik's letter, Commission Administrator Robert Tembeckjian said in a statement to CNBC, "All matters before the Commission on Judicial Conduct are confidential according to law, unless and until a judge is found to have committed ethical misconduct, and a decision to that effect is issued."

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