Premier Helen Zille's views on colonialism are inconsistent with what the Democratic Alliance (DA) stands for, party leader Mmusi Maimane said on Monday.
The matter had "serious consequences", he said during a door-to-door campaign in Pietermaritzburg.
"Any view that seeks to undermine the pact that the DA took in 1994 to work together as all races is a view that is inconsistent with what the DA stand for."
She had been referred to a disciplinary hearing and he would let the party’s federal legal commission do its job. The rule of law applied to everyone in the party, regardless of their position.
“I don't share the views and we will continue to fight for a South Africa for all, a South Africa where all races can stand together."
Zille caused an uproar on social media when she tweeted on Thursday that not every aspect of European colonialism was bad.
"For those claiming legacy of colonialism was only negative, think of our independent judiciary, transport infrastructure, piped water etc," she wrote.
"Getting onto an aeroplane now and won't get onto the Wi-Fi so that I can cut off those who think EVERY aspect of colonial legacy was bad."
She later apologised and said her tweets were not intended as a defence of colonialism.
Maimane was speaking to residents of Ward 32 in the city ahead of their by-election on March 29. The ward’s DA councillor resigned and joined the African National Congress within 30 days of the local government elections in August last year.
Maimane told residents that the party wanted to do away with corruption and deliver services to the people.
He met unemployed Joyce Frankis, 49, who lives with her nine children and four grandchildren.
Frankis told Maimane that life was unfair. They applied for government jobs but were overlooked because of nepotism and corruption, she claimed.
Maimane said the DA intended creating opportunities for people like Frankis.