The ANC's Smuts Ngonyama has resigned because he was no longer able to "tolerate or embrace" the recent disrespect of authority in the party.

It was offensive and "not something we can celebrate", he said at a press conference announcing his resignation from the ANC in Johannesburg on Thursday.

Ngonyama is the latest of a slew of ANC members who have left the party to join the Congress of the People (Cope), started by former Defence Minister Terror Lekota, with former Gauteng Premier Mbhazima Shilowa at his side.

"It is imperative ... that I continue to contribute towards the development of South Africa and should do so where I will be able to make the maximum impact," Ngonyama said.

He scotched reports that he was one of the funders of the new party. He also could not detail the position he would hold, saying: "Position doesn't matter, what matters is space for me to make my contribution and that is what I am looking forward to".

"I now believe that the Congress of the People is a welcomed addition to our political landscape. We have the opportunity to ensure that the dream of non-racialism, non-sexism, and a united, prosperous South Africa remains within our reach".

Ngonyama said he believed politics was about power. "You don't take to the field with an idea of losing, (but) ... with an idea of winning. I think Cope is aiming to win, however the test will be in the field; the test will be with the people of South Africa. They will express their preference."