Former Market Basket CEO and President Arthur T. Demoulas was deposed Monday in an ongoing legal battle over his status as head of the iconic supermarket chain as a pivotal court date looms.

Market Basket’s board of directors fired Demoulas in September and immediately filed a suit in the Delaware Court of Chancery, where the company is incorporated, against him to uphold their decision.

Demoulas then countersued, claiming his termination constituted “unlawful actions… not motivated by any rational business purpose or to advance the Company’s best interests.”

The deposition comes as both sides prepare to face each other in court next month.

The director-plaintiffs in the case argued in their filing that Demoulas had a history of “ignoring and stonewalling” the board. They claim that Demoulas wouldn’t accept their oversight, declining to bring decisions to the board before approving them and refusing to bring budget information to board meetings, which Demoulas denied.

The ousted leader argued that the board members against him have been installed by his siblings, who hold a significant stake in the company and are also embroiled in pending family trust litigation in Massachusetts.

About 60% of the company stock belongs to Demoulas’s three sisters. Demoulas himself owns about 28.4% of the company, while another 10.3% of the stock is held in a trust for the 14 children of the four siblings.

With 90 Market Basket locations around New England, the company rakes in $8 billion in revenue annually.

The latest suit comes after years of turmoil amidst Market Basket leadership and ownership that has played out both in the media and in court.

Demoulas was fired and then reinstated in 2014 following a battle with his cousin Arthur S. Demoulas over control of the company. A worker walkout, customer boycott, and subsequent buyout of the company by Artie T and his siblings put him back at the helm.