The African National Congress (ANC) is living within its own "bubble" and it is not honouring the confidentiality of the no confidence vote against President Jacob Zuma, former minister for intelligence services Ronnie Kasrils said on Thursday.

"They are not honouring this; that's disgraceful," Kasrils told News24.

Kasrils was speaking on the side-lines of the colloquium of civil society at the University of the Witwatersrand in Braamfontein.

"If you... then own up [to voting against Zuma] you actually undermine the whole question of a confidentiality vote and how that affects other people," he said.

Last week, African National Congress secretary general Gwede Mantashe said at least three MPs would be disciplined for openly admitting that they voted with the opposition for Zuma's removal during the historic motion that saw a secret ballot used for the first time.

Praise for Hanekom

Former finance minister Pravin Gordhan, former tourism minister Derek Hanekom and senior ANC MPs Makhosi Khoza and Mondli Gungubele are widely expected to face a disciplinary inquiry as they have publicly stated that they would vote with their conscience.

Mantashe wrote to Hanekom on Sunday, asking him to explain why he should not be removed as the chair of the national disciplinary commission following his "Twitter commentary" urging that Zuma be voted out.

"So if I was comrade Derek I would simply say: 'In terms of that vote, it was a vote in confidence; it is my secret and I am not saying anything further,'" Kasrils said.

Kasrils hailed Hanekom, Khoza and Gordhan for doing what is "necessary for the good standing of the ANC to correct the party.

"I can associate with that approach: I took a stand in 2014 to try and shake the ANC up, because it lives within its own bubble."

Kasrils shocked the country when he said he would not vote for the ANC in the 2014 election. He launched what he called the "Vote No" campaign.

On Tuesday, August 8, an estimated 30 to 40 ANC members of Parliament supported a motion on no confidence in President Zuma, brought by the opposition.