(Reuters) - Steven Donziger, the American lawyer who spent more than two decades suing Chevron Corp over pollution in the Ecuadorian rainforest, may have to be represented by his ex-lawyer in a trial for criminal contempt in Manhattan federal court slated to begin in less than two weeks, a judge ruled on Friday.

Senior U.S. District Judge Loretta Preska ordered Donziger's former lead defense attorney, Andrew Frisch of Schlam Stone & Dolan, to take the reins after the court disqualified two of Donziger's attorneys and if another two continue to decline or are unable to appear.

In her order, Preska said that the disqualification of two attorneys on Donziger's defense team had the appearances of "delay tactics." Another two of his lawyers have refused to travel to New York out of concerns over contracting COVID-19, and say they cannot participate by video or act as lead counsel.

Preska rejected Donziger's arguments that conflicts of interest, including over a dispute about legal fees, barred Frisch, who withdrew in July, from serving as defense counsel.

The judge said the court had conditionally allowed Frisch to withdraw if it did not affect the trial date.

"That potentiality has now come to pass, thereby voiding Mr. Frisch's conditional withdrawal and requiring his appearance as Mr. Donziger's attorney at trial," she said.

Donziger directed an inquiry for comment to his lawyers.

His attorney Martin Garbus of Offit Kurman, one of the two lawyers who has not been disqualified but refuses to travel to New York amid the coronavirus pandemic, said a trial with Frisch would not be "a constitutionally protected case."

"Donziger is being forced to go to trial with a lawyer who doesn't want to be in the case, who doesn't get along with Donziger, and claims that before Donziger goes ahead with the trial he should pay him additional moneys," he told Reuters.

Nine years ago, Donziger had won a $9.5 billion judgment against Chevron in an Ecuadorean court, but was unable to enforce it after a U.S. judge found it had been obtained through fraud.

In a decision published on Aug. 14, a state appeals court disbarred the Harvard Law School graduate in New York.

Now, the embattled lawyer faces a Sept. 9 trial over six counts of criminal contempt. Donziger stands accused of failing to obey the court, including by failing to undergo in time a forensic inspection of his electronic devices and to surrender his passport. The prosecution, the United States, is represented by Seward & Kissel.

Neither Frisch, attorneys for the prosecution nor Chevron responded to requests for comments.

The case is USA v. Donziger, U.S. District Court for the Southern District of New York, No. 1:19-cr-00561-LAP-1.

For USA: Rita Glavin, Brian Maloney and Sareen Armani of Seward & Kissel

For Donziger: Andrew Frisch of Schlam Stone & Dolan