The Port Elizabeth High Court has ordered that by-elections be held within 90 days to fill vacancies in Wards 35 and 37 in the city's Northern Areas.
These wards were held by former DA councillors, Trevor Louw and Neville Higgins, who both bailed on the party after the coalition government of Athol Trollip was ousted.
In a 23-page ruling on Tuesday, Judge Edna Revelas found that their membership had been properly terminated.
In his reaction, the DA's Provincial Leader Nqaba Bhanga said the party was happy with the judgment because there was no way a councillor could sit in the seat of a political party while disciplinary processes were being followed.
"It vindicates not only the DA but many political parties where people decide to cross the floor and still want to remain in the seats that they have," said Bhanga. "The court has affirmed that it cannot happen like that and parties must conduct proper disciplinary processes and remove councillors."
However, Judge Revelas dismissed an application by the DA with respect to the membership of another councillor Victory Manyati, who effectively sided with the ANC by abstaining in a vote of no confidence against Trollip in August.
Bhanga said it was "bizarre" that the court dismissed the DA's case against Manyati but that they respected the ruling.
He said the DA would nevertheless be starting the disciplinary processes against Manyati and hoped to conclude the matter within a few weeks.
Bhanga said he was confident that the DA would win the by-elections in the city's Northern Area's.
