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.

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

Albertsons said it is calling off its merger with Kroger and is suing the rival grocery chain for breach of contract.