Johannesburg - Cape Town Mayor Patricia de Lille was not informed of DA Cape Town metro chairperson Grant Pascoe's defection to the ANC, it emerged on Monday.
"I have just learned that the mayoral committee member for tourism, events and marketing [Team], [Pascoe], has changed his political affiliation from the Democratic Alliance to the African National Congress," De Lille said in a statement.
"As he has chosen to take this action before doing me the courtesy of informing me, I can only assume that he has chosen to find a new political home due to his inability to live up to the standards required of DA public representatives."
De Lille listed shortcomings in his performance.
These included not always attending meetings of the city's political and administrative leadership, poor preparation when he did attend and poor management of the Team.
"In light of the above, it is difficult to see anything beyond naked opportunism in such a once strident critic of the ANC so quickly joining them," she said.
"I certainly hope that any future constituents of councillor Pascoe’s remember his points of principle, or lack thereof."
The ANC announced earlier in the day that Pascoe had defected.
"Councillor Pascoe joins an overwhelming number of South Africans, who despite finding themselves in other political parties, recognise the ANC as the only organisation with the track record, capacity and determination to build a South Africa," spokesperson Jackson Mthembu said in a statement.
"Comrade Pascoe joins as an ordinary member of the organisation, and will assist our efforts to win back the Western Cape."
Pascoe served as a DA councillor for more than 13 years and was a member of the mayoral committee from 2006.
DA Western Cape leader Ivan Meyer echoed De Lille's sentiments.
"The fact is that Mr Pascoe was imminently going to be demoted out of the Mayoral Committee [Mayco] in Cape Town for poor performance.
"He knew that things weren’t going well in his portfolio, and that he was going to be sacked imminently," Meyer said in a statement.
A number of DA members have defected to the ANC, just months before the 7 May general election.
Last month, DA MP Beverley Abrahams defected during a sitting of the National Council of Provinces.
She resigned from the party in a statement, which she read out during the sitting.
Abrahams was the DA member for Gauteng in the NCOP.
Four DA councillors from Ekurhuleni and Johannesburg joined the ANC in February.
The defection of the two from Ekurhuleni was announced on 11 February, the day of the DA's march to the ANC's Luthuli House headquarters for real jobs.
The two from Johannesburg were announced on 27 February.
Toni Molefe and Sipho Masigo served as DA proportional representation councillors in the City of Johannesburg.
Molefe was DA deputy chief whip and Masigo was the party's deputy chairperson in Gauteng.
Four DA councillors in Tshwane were also set to defect to the ANC.
ANC Tshwane deputy chairperson Mapiti Matsena said last month that they would leave the DA in pairs during the next two council meetings.