In a statement issued late on Monday, Mr. Mistry hinted at taking his fight with the Tata Group on an external forum away from the shareholders.

In a surprise move, Cyrus Mistry on Monday resigned from the boards of all publicly listed companies of the Tata group after a bitter, eight-week boardroom battle against Ratan Tata’s ‘illegal coup to unceremoniously remove’ him as the chairman of Tata Sons on October 24.

However, Mr. Mistry plans to escalate the fight. He is gearing up for a long-drawn legal battle. After tendering his resignation to the companies in the group, Mr. Mistry confirmed that he was going to drag Tata Sons and its board members to court in his fight for “governance” within the $103 billion salt-to-software conglomerate.

“I will fight for the future, of the Tata Group, that is at stake and not my office. I have resigned from the operating companies and not Tata Sons,” Mr. Mistry told The Hindu. Asked why he was resigning now after engaging in the tussle that saw investor wealth erode by about Rs.1 lakh crore, Mr. Mistry said, “My staying and being a constructive part of the board was not eroding the wealth. But, taking out a person for no reason erodes wealth. Cohesive action with your shareholders, board and board members takes out wealth. That is the way I look at it. And, I think, effectively today is the right time to change the forum.”

Mr. Mistry said in a statement, “Having deeply reflected on where we are in this movement for cleaning up governance and regaining lost ethical ground, I think it is time to shift gears, up the momentum, and be more incisive in securing the best interest of the Tata group.”

Mr. Mistry had decided to step down “for an effective reform; and, in the best interests of the employees, public shareholders and other stakeholders of the Tata group, it would be better served by my moving away from the forum of extraordinary general meetings (EGMs).”