Balindlela resigned as a member of the National Assembly and of COPE, which she joined in 2008 after the ANC sacked her as premier, to join the DA, which she called "the future" of national politics.

The ANC described Balindlela as a political liability who had failed to perform while she was a premier.

ANC spokesman Jackson Mthembu disputed a DA press statement that identified Balindlela as a former member of the powerful ANC national executive committee.

"Nosimo Balindlela has never been an NEC member.

"In terms of party leadership, the furthest that she rose in leadership terms was being a regional chairperson of the ANC in Eastern Cape, and she sat in the [provincial executive committee] as an ex-officio member by virtue of being the premier of Eastern Cape," Mthembu said.

"It is misleading to associate Balindlela with the ANC as she was a COPE member before joining the DA.

"Balindlela was the least effective premier in Eastern Cape, hence she was recalled. If there is anything that the DA has netted, it is a political liability that will further alienate the party in Eastern Cape," Mthembu said.

Balindlela said her decision to cross the floor had been influenced by infighting in COPE .

"I cannot say COPE is sinking because we have got a great leader in Mosiuoa Lekota. But ... I think the future is with the DA."

DA leader Helen Zille said that though her party had criticised Balindlela's performance as premier, "she did her best to deal with the corruption she faced".

"She was shipwrecked by the conflict between the supporters of Thabo Mbeki and Jacob Zuma".

COPE said it respected Balindlela's decision.