But the DA, which described Balindlela’s departure as "a blow”, said the former premier of the Eastern Cape told them she had been wooed back to the ANC by President Cyril Ramaphosa.
ANC provincial secretary Lulama Ngcukaitobi said Balindlela had engaged with the party’s leadership before taking the decision, and that she had expressed her concern about the direction in which the DA was moving.
“What broke the camel’s back for her is what is happening in Cape Town to De Lille and how she is being treated. And also the reaction to the tweet by Maimane on racial inequality from within the DA.
"But as the ANC, what we can say is that we have spoken with her, and as a cadre who has learnt a lot through the responsibilities she was given by the ANC, she must come back to us.
"There is a lot she can do here,” Ngcukaitobi said.
Balindlela left Cope and joined the DA in 2012. She resigned from the ANC after she was sacked as premier following the ANC's 2007 conference in Polokwane.
She was one of the provincial leaders viewed as close to then president Thabo Mbeki, who lost the ANC's presidential race to former president Jacob Zuma.
Ngcukaitobi said there were no conditions for Balindlela to rejoin the governing party.
“She is an experienced cadre who has worked in the provincial government both as MEC and as premier, so we are excited to have her back and we will use her experience to help ensure that we improve the lives of our people in the Eastern Cape.
"We expect all the ANC members who left us and joined the DA, because of the problems we (ANC) were going through, to come back,” he added.
Balindlela was a DA MPL in the Eastern Cape Legislature and crucial to the party’s efforts to dismantle the ANC’s heartland.
In a statement yesterday, the DA's provincial leader in the Eastern Cape Nqaba Bhanga slammed Balindlela’s resignation as “misguided”.
According to Bhanga, Balindlela had told the DA’s leadership that her decision to abandon the party came after she was promised a position by Ramaphosa.
“She told us, as the leadership in the province, and the national leadership that she had been approached by President Ramaphosa and has been promised a post,” Bhanga said.
Attempts to get comment from Balindlela were unsuccessful and Bhanga refused to disclose the details of the job promise to her by Ramaphosa.
She insisted that only Balindlela could disclose the details.
Bhanga said Balindlela’s decision to leave the party was a blow, as she was viewed as a "mother" by many.
“There is a sense of loss in the DA after her decision. We have plans of taking over this province.
"But we respect her decision and we appreciate how she has handled the matter, with dignity,” Bhanga said.
But she emphasised that Balindlela did not tell the DA leadership about her problems with how it treated De Lille.
“She told us she was approached by the ANC president (Ramaphosa) and she leaves with a happy heart, because we treated her like a queen,” Bhanga said.
ANC spokesperson Pule Mabe could also not be reached for comment.
DA federal council chairperson James Selfe described Balindlela’s decision to abandon the official opposition for the ANC as "confusing".
“It is perplexing that Nosimo has chosen a party that created a corrupt system of disorder and chaos that oppresses the people of the Eastern Cape.
"But Balindlela’s departure will not have any impact on our electoral prospects.
"The DA remains focused on our mission to bring change to the Eastern Cape. Change that stops corruption; change that creates jobs; and change that makes our citizens safer.” Selfe said.
But he would not be drawn on the ANC’s statement that Balindlela left the DA because of how De Lille and Maimane had been treated.