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.