Acting Democratic Alliance (DA)Western Cape leader Bonginkosi Madikizela says former party leader Helen Zille's controversial tweets about colonialism on Thursday may result in a loss of voter support.

"Without a doubt these comments have a negative impact to the people we [the DA] are trying to attract who are black people," Madikizela told News24.

"There is no way we can defend it. Of course it has offended people who were oppressed by colonialism. It will make our work a bit difficult."

Madikizela said he, like many other DA members, was also offended by Zille's remarks.

DA party leader Mmusi Maimane has since referred the matter to internal party structures. Zille also apologised on Twitter an hour after making her remarks. She did not respond to a request for comment on Thursday.

Zille said on Thursday morning in a series of tweets: "For those claiming legacy of colonialism was ONLY negative, think of our independent judiciary, transport infrastructure, piped water etc."

A second tweet read: "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."

Resignation calls hypocritical

Madikizela said: "This is bringing to the floor the debate of white superiority...when you imply Africa would not have what it...has without whites, you are saying Africans are incapable of doing it themselves."

However, Madikizela said the calls for Zille's resignation were hypocritical.

"The people making these calls are making it for opportunistic reasons. They themselves come from parties which have done far worse than what Helen Zille has done," he said.

Madikizela said that while many DA members were upset about Zille's comments, none have threatened to leave the party.

"We have overcome much worse things. Former members of the National Party, ID, PAC and even from the ANC came together to form the DA," he said.

"From time to time we will differ, but it is then important that we don't damage the brand, even though we come from different places, it is important to work from our shared values and shared ideals. And that's not an easy thing to do."

DA federal executive chairperson James Selfe said the DA's disciplinary chairperson Glynnis Breytenbach will be meeting with Zille on Monday to initiate disciplinary processes.

'Imperialist-funded regime change agenda'

He said he doesn't expect the matter to be drawn out as it was "relatively simple".

The DA constitution makes provision for a member to be suspended pending investigation, but Selfe said the provision is implemented only when there is a risk that the defendant might influence the investigation.

The final outcome of a DA disciplinary process needs to be adopted by the federal executive, of which Zille is a member.

Selfe said Zille would excuse herself during the meeting when the matter is due to be discussed.

Selfe said the party has also not received any correspondence from Julius Malema or the Economic Freedom Fighters, which has partnered with the DA in some municipalities, tweeted that it will be meeting with the DA to discuss Zille's remarks.

Meanwhile the ANC Women's League (ANCWL) said Zille's views reflected the views of the DA as a whole.

"Her conscious remarks should not be analysed in isolation from the imperialist-funded regime change agenda that seeks to remove the democratically elected government," the ANCWL said in a statement.