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.

Albertsons said Kroger has failed to make best efforts to secure regulatory approval of the merger of the supermarket chains.

Kroger is accused of wilful contractual breaches and of failing to uphold its obligation of good faith and fair dealing.