The court ordered the status quo as was prevalent on 23 June and held that a general council meeting of the party conducted on 11 July was null and void.
The general council, the AIADMK's highest decision making body, had "expelled" O Panneerselvam (OPS) and some of his supporters from the party amid a leadership tussle between him and EPS. Subsequently, the latter was chosen as the party's general secretary.
Justice G Jayachandran ruled that only the coordinator and the joint coordinator is permitted to conduct a general council meeting. He also suggested an observer to be nominated for the meeting.
"This is a big victory for OPS. The court has accepted our argument and delivered a judgment. The court has rejected the arguments and decisions taken in the General Council meeting. We are waiting for the detailed order. The order clearly says the post of coordinator still exists," said OPS' counsel Thirumaran.
Supporters of OPS also celebrated the verdict in front of his home by bursting crackers and distributing sweets.
OPS Hails Judgment as 'Historic'
OPS, meanwhile, called the verdict "historic" and said that his faction will welcome all those who wish to join them.
"This is a historical judgement. We got full victory because of this judgement. If anyone comes forward to join us, we'll welcome them. AIADMK cadre's wishes came true. We will respect and act in accordance with High Court judgement," he said.
The leader also said that there was no place for dictatorship in the AIADMK and that everyone must unite once again under the party's banner.
"There is no place for dictatorship in party. All should unite and those who left party must return. Sacrifice & patience are qualities a leader must possess. If needed, we'll discuss (on unison of OPS and EPS), party cadres will not change," OPS was quoted as saying by ANI.
'High Court Verdict Not Final': EPS Supporter
On the other hand, D Jayakumar, a supporter of EPS, said that the high court's verdict was not final.
"Every decision was taken as per AIADMK bylaws. The high court's verdict is not final. We will discuss and take future legal course in this regard," he said.
Jayakumar also said that the court had provided temporary relief to OPS and that the the party would deliberate upon the verdict.
Following the general council's meeting on 11 July, OPS had lodged a complaint with Chief Election Commissioner of India Rajiv Kumar, urging him not to accept the decisions taken during the "illegal" meeting.
In his letter to the commissioner, written on the AIADMK's letterhead, OPS asserted that he still continued to be the party coordinator and treasurer of the AIADMK.
(With inputs from ANI.)