Kroger’s proposed merger with fellow grocery chain Albertsons ended in acrimony this week as a judge granted the Federal Trade Commissions’s request to block the deal on antitrust grounds. Albertsons then sued Kroger for allegedly not fulfilling its contractual obligations.

For the two grocery rivals, which had been on track to marry their numerous supermarket banners, the lawsuit amounts to a corporate divorce battle.

In an historic ruling for labor and antitrust advocates, a federal judge blocked the $25 billion merger of grocery giants Kroger and Albertsons.