The six former associates who have accused Jones Day of systematically discriminating against women at the firm asked a federal judge Wednesday to conditionally certify the case as a collective action under the Equal Pay Act.

If granted, the certification would allow the plaintiffs to alert all female associates who have worked at Jones Day since April 3, 2016—three years before they initiated the $200 million lawsuit—of their right to opt in.

The six named plaintiffs—Nilab Rahyar Tolton, Andrea Mazingo, Meredith Williams, and  Jaclyn Stahl, who all worked for the firm in California, along with former Atlanta associate Saira Draper and former New York associate Katrina Henderson—have alleged that the black box compensation structure employed by the firm helps enable discriminatory pay.

"Plaintiffs worked in multiple Jones Day offices and practice groups, and each has been subjected to a common compensation practice that results in women earning less than men for substantially equal work," they said in the filing in D.C. federal court. "All are challenging the same compensation policy, under which every associate's compensation is determined in a 'black box,' with final decisions made by the Firm's Managing Partner, Stephen J. Brogan."

The 27-page brief, filed by the women's lawyers at Sanford Heisler Sharp, bolsters allegations made in earlier pleadings with deposition testimony from the six women. For example, in regard to Brogan's purported final control over associate compensation, Mazingo, who is now an associate at Orrick, Herrington & Sutcliffe, stated, "I know that any [salary] recommendations ultimately would have been made to Steve Brogan, who signed each letter."

Henderson, now an in-house attorney with Amazon, alleged that a Jones Day practice leader told her there was "nothing he could do" about her compensation, while Williams, now an associate with Rutan & Tucker, described how she was discouraged from challenging her compensation and requesting a raise because it would "attract the wrong attention" and "reflect badly" on her.

The plaintiffs also sought to support their claims, challenged by Jones Day, that the firm promised pay along the "Cravath Scale" in all geographical markets. Williams, who worked in the firm's Irvine, California, office, said that when preparing to speak with recruits at the firm, she was told that she should describe Jones Day's compensation in terms of "market" pay, and that everyone understood "market" to be synonymous with "Cravath."

Several of the plaintiffs also listed the names of their male colleagues who allegedly outearned them on raises, while other comparative details in the filing were redacted, along with parts of their other allegations against the firm.

In addition to denying that it pledged to pay "Cravath Scale" wages across all geographic markets, Jones Day has highlighted what it described as the professional failings of several women levying accusations against the firm.

The firm has also asked a federal judge to strip the lawsuit down to a core question of whether Jones Day intentionally discriminated against the six women, removing claims under the Equal Pay Act and several other statues and legal theories. The parties are scheduled to meet in court Dec. 16 for oral argument on the subject.

A representative for Jones Day did not immediately respond to a request for comment.