Judge Edward Chen, U.S. District Court for the Northern District of California

A federal judge overseeing a lawsuit against Uber Technologies on Tuesday considered the ride-sharing company’s motion to disqualify one of the plaintiff’s lawyers on the case due to his previous position litigating alongside Uber on behalf of the U.S. Chamber of Commerce.

Judge Edward Chen of the U.S. District Court for the Northern District of California said at a hearing on Uber’s motion that Warren Postman—who is now part of the Keller Lenkner team representing Diva Limousine in its suit against Uber—had a “common interest” with Uber when he previously collaborated with the company’s lawyers on the chamber’s challenge to a Seattle collective bargaining ordinance for ride-hailing drivers.

Although there was no formal joint defense agreement between the parties, Chen said the fact that Uber was a co-plaintiff with the chamber in the lawsuit challenging the Seattle law could create some sort of common interest.

“If there is a credible assertion that the parties acted under, then understanding that there is some kind of joint defense or common interest privilege, some documents were shared … then I have to go with the broad brush of substantial relationship,” said Chen, chewing over whether Postman and his firm should be disqualified.

Attorneys for Uber at Morgan, Lewis & Bockius filed a motion to disqualify Keller Lenkner last month, arguing that Postman’s conflict must be imputed to the entire firm.

Uber’s lawyer, Brian Rocca, told the court on Wednesday that Postman’s co-counsel at the chamber, Steven Lehotsky, had confirmed that he and Postman received confidential information from Uber’s counsel about the ride-sharing company’s core legal strategies and business model as a result of a partnership between the chamber and Uber in the Seattle litigation.

“The legal updates are one thing, but the core work product that goes to the heart of Uber’s business model is another thing,” Rocca said.

Lawyers at Robins Kaplan and Keller Lenkner sued Uber in September, claiming that the company saves millions in required benefits and payroll costs via its classification of drivers as contractors rather than employees. They allege the misclassification allows Uber to target their client, Studio City-based livery service Diva Limousine Ltd., with “below-cost and anticompetitive pricing” and saves Uber nearly $500 million in California annually.

Keller Lenkner name partner Travis Lenkner said Wednesday that plaintiffs do not dispute that Uber and the chamber were co-plaintiffs in the Seattle litigation and could have a common interest. However, because Uber’s materials were shared widely with the chamber, they should not be considered confidential, he argued.

“There is nothing confidential there,” Lenkner said. “This issue has been litigated in courts and other proceedings … anything you have been saying … is out there.”

Lenkner further suggested that Uber waived its privilege by delaying its disqualification motion weeks after Diva filed its complaint. Uber’s motion was a “strategic move” to disqualify Keller Lenkner from the litigation, he said.

“These are all tactical conduct by Uber,” said Lenkner. “They should have raised the question with us.”