A federal judge refused to step down from a "clean diesel" fraud trial against Volkswagen next week, calling the plaintiffs' concerns of bias an "abrupt about-face" from their previous arguments.

Lawyers for 10 plaintiffs pursuing fraud damages had filed a motion to disqualify the Northern District of California judge, Charles Breyer, based on "concerns about appearance of bias." They cited his ruling this month to make the trial's first phase, slated to begin Monday, a bench trial focused on the fairness of the "clean diesel" settlements, the same ones that he approved.

In a Friday order, Breyer found he had no conflict in overseeing the trial.

"The court takes their concerns seriously and has carefully evaluated the request for disqualification," he wrote of the plaintiffs. "However, it is clear that the rulings and statements plaintiffs complain of do not constitute the rare circumstances that would justify recusal."

He also refused to refer the disqualification matter to another judge, concluding that the plaintiffs' affidavit was "legally insufficient" and that their motion, filed the day after jury selection and two days following their support of a bench trial, was made for the purpose of delay.

"Plaintiffs offer no explanation for their abrupt about-face," Breyer wrote. "Given this unexplained change of position, after trial had commenced and less than a week before the start of evidence, the court concludes the motion to disqualify was 'interposed for delay.'"

Volkswagen attorney Robert Giuffra, a partner at Sullivan & Cromwell in New York, wrote in an email, "We look forward to the start of the trial next week."

Bryan Altman, of Altman Law Group in Los Angeles, one of the plaintiffs' attorneys who filed the disqualification motion, did not respond to a request for comment.

The disqualification motion is the latest twist in a case that followed Volkswagen's $14.7 billion class action settlement in 2016 and $1.2 billion agreement in 2017 to resolve consumer claims associated with its "clean diesel" scandal, in which the automaker admitted to cheating on emissions tests. Under the settlements, Volkswagen agreed to provide cash and repairs to customers.

The plaintiffs are seeking damages under the California Consumer Legal Remedies Act, which provides for compensatory and punitive damages, as well as attorney fees.

Last month, plaintiffs sought to bring former FBI Director Louis Freeh into the case, prompting Volkswagen to file a motion to disqualify him as an expert. Breyer excluded Freeh as an expert on Feb. 11, mooting Volkswagen's disqualification motion.

In a Feb. 4 summary judgment ruling, Breyer found that Volkswagen's affirmative defense to plaintiffs' consumer fraud claims should go before him, rather than a jury. In particular, Volkswagen planned to argue that its "clean diesel" settlements provided an "appropriate correction" to any consumer fraud claims.

In Friday's order, Breyer said he found no conflict in determining the consumer fraud defense under California law because he approved the settlements under the Federal Rule of Civil Procedure 23.

"The court's determination as to the applicability of the defense will not be guided by or a reflection on—the adequacy of the class settlements as a resolution of the class claims," he wrote.

In fact, his involvement in the settlements would aid in ruling on Volkswagen's defense, Breyer wrote. He cited a Jan. 17 letter in which the plaintiffs wrote that the judge was "in the unique and best position to decide the issue, having handled the class action case and knowing what was offered as part of the class action settlement, when it was offered, what conditions were involved with it, as well as other matters."

"The court finds plaintiffs' earlier position persuasive and concludes that having presided over the class settlements will aid rather than hinder its evaluation of their sufficiency under the CLRA," he wrote.

After the bench trial concludes, a jury plans to arrive on Tuesday for the next phase focused on compensatory damages. Another phase about punitive damages, if necessary, would follow immediately.