Donald J. Trump, a week away from standing trial in Manhattan on criminal charges that he falsified records to cover up a sex scandal, has indicated he plans to file a lawsuit against the judge overseeing the case.

Court records showed on Monday that Mr. Trump was filing an action against the judge, Juan M. Merchan, though the papers were not immediately made public. An online court docket where Mr. Trump is expected to file the so-called Article 78 action — a special proceeding that can be used to challenge New York state government agencies and judges — showed that the related paperwork was sealed.

Two people with knowledge of the matter said that Mr. Trump’s lawyers on Monday planned to file the action calling on an appeals court to delay the trial and to challenge a gag order that Justice Merchan recently imposed on the former president. The order prevents Mr. Trump from attacking witnesses, prosecutors and the judge’s own family.

Mr. Trump’s unorthodox move — essentially an appeal in the form of a lawsuit — is unlikely to succeed, particularly so close to trial.

And the appeals court might act fast to reject it. A single appeals court judge will most likely issue a preliminary ruling on Monday, setting up a full five-judge panel to consider Mr. Trump’s request in the coming days.

In a separate filing with the appeals court on Monday, Mr. Trump was expected to ask the court to move the trial outside Manhattan. The request reflects his deep unpopularity in the solidly Democratic borough.

Mr. Trump’s lawyers have tried several times to delay the trial, but this is their first attempt in an appeals court. The former president, who is again the presumptive Republican presidential nominee, is aiming to push all four of his criminal cases past Election Day. If he wins, the cases are likely to grind to a halt.

This latest effort to stop the Manhattan case — the first prosecution of a former U.S. president, and possibly Mr. Trump’s only criminal case to make it to trial this year — comes as Mr. Trump is separately calling on Justice Merchan to recuse himself from the case.

Mr. Trump and his lawyers argue that the judge has a conflict of interest, citing his daughter’s position at a Democratic consulting firm that worked for President Biden’s campaign in 2020.

Mr. Trump has repeatedly assailed Justice Merchan’s daughter on social media and posted articles with her picture, leading the judge to expand the gag order to bar Mr. Trump from attacking her.

The judge could rule on the recusal request in the coming days. He rejected Mr. Trump’s first recusal request, filed last year, and is likely to do the same this time.

In a response to Mr. Trump’s most recent request, prosecutors for the Manhattan district attorney’s office, which brought the charges against Mr. Trump, wrote that Mr. Trump “predominantly repeats the same arguments that he made in his first recusal motion more than ten months ago and that this court previously considered and rejected.”

The prosecutors added that the recusal request was based on “a daisy chain of innuendos.”

A spokeswoman for the district attorney, Alvin L. Bragg, declined to comment on the Monday appeal.

Lawsuits against judges are unusual, but this is not Mr. Trump’s first attempt to use that tactic to try to delay a trial. Last year, he sued the New York judge presiding over his civil fraud trial — an effort the appeals court ultimately rejected.

Kate Christobek contributed reporting.