Cape Town - Veteran politician Patricia de Lille told a media briefing that the decision to kick her out was a victory for conservatives within the Democratic Alliance.
"If they think it's a victory today, it's a victory for the conservative people in the DA who don't want to see transformation in the City of Cape Town."
Earlier on Tuesday, the DA announced de Lille has ceased to be a member of the party, thereby ending her seven-year rule as mayor of Cape Town.
The DA said deputy mayor Ian Neilson would take over in an acting capacity, while De Lille, in trademark style, hit back and accused the party she has served for a decade and a half of having a regressive agenda.
Natasha Mazzone, the deputy chairwoman of the DA's federal council, early on Tuesday told a media briefing the "cessation of her membership" was based on the fact that De Lille breached the party's constitution by declaring her readiness to resign on a radio talk show late last month.
De Lille's assertion that she was "ready to walk away" sealed her fate, Mazzone said.
Mazzone said section 3.5.1.2 of the party's constitution stipulates that a member ceases to be a member when he or she "publicly declares his or her intention to resign and/or publicly declares his or her resignation from the Party”.
She then quoted from an interview with 702 Radio on April 26 where De Lille told Eusebius McKaiser that she would resign from the country's second biggest party as soon as she had cleared her name in a bitter dispute with its leadership.
"I’ve said it many times before, Eusebius, you know, the writing’s on the wall that people don’t want me for whatever reason... I will walk away," De Lille was recorded as saying in the interview.
James Selfe, the chairman of the DA's federal executive, said while Neilson would serve as acting mayor, adding that the party would seek to elect a permanent mayor as soon as possible for the sake of stability and rebuilding trust.
Selfe conceded that he did not think the decision to terminate De Lille's membership of the party would end a bruising battle between her and the DA, which has repeatedly landed up in the Cape Town High Court.
"I would like to think that the saga ends today, but somehow I doubt it."
De Lille and the Democratic Alliance have been involved in open hostility for months after colleagues at the city council aired maladministration and corruption allegations against her. Two of her allies in the city administration lost their jobs following an internal investigation but De Lille has strenuously denied any wrongdoing.
She has accused the party of trying to oust her to frustrate efforts to bring about greater social equality in the city, earning a stinging rebuke from Selfe who told media the claim was nonsense.
De Lille has in recent weeks sought to force the DA through the courts to give her access to documentation that informed its decision, on February 14, to charge her with misconduct after a separate political investigation, headed by DA chief whip John Steenhuisen.
Mazzone said on Tuesday it had hoped the disciplinary process would be concluded within two months but that De Lille had chosen to challenge the process repeatedly by "introducing a number of interlocutory matters, including that the hearing be open to the public and that it should be conducted by independent persons".