Setting the stage for what’s likely to be a knock-down fight, financial industry lawyers led by Gibson Dunn & Crutcher partner Eugene Scalia faced off in court Tuesday against counsel for the U.S. Commodity Futures Trading Commission over rules governing the $600 trillion market for cross-border swaps.

In a preliminary hearing before U.S. District Judge Ellen Huvelle in the District of Columbia, the lawyers laid out key points of contention in the suit filed by the Securities Industry and Financial Markets Association, the International Swaps and Derivatives Association and the Institute of International Bankers in December.