The former head of communications for South Africa's ruling African National Congress (ANC) has resigned from the party to join a breakaway movement.
Smuts Ngonyama was quoted as saying he was unhappy about a recent disrespect of authority in the ANC.
The ANC split follows a bitter power struggle between party leader Jacob Zuma and former President Thabo Mbeki.
The ANC forced Mr Mbeki to step down as president in September - a move which angered some of his allies.
The ANC issued a statement saying they welcomed Mr Ngonyama's decision and wished him luck.
At a press conference on Thursday, Mr Ngonyama said he wanted to contribute to South Africa's development, and thought he could best do so by joining the new Congress of the People.
"I now believe that the Congress of the People is a welcomed addition to our political landscape," he said, according to the South African Press Association.
"We have the opportunity to ensure that the dream of non-racialism, non-sexism, and a united, prosperous South Africa remains within our reach."
Observers expect a number of other senior ANC members to resign ahead of the launch of the breakaway party, scheduled for December.
The party's registration has been delayed because the name it had initially chosen, the South African National Congress, was challenged by the ANC, while the second choice name - the South African Democratic Congress - had already been taken.
The ANC says it intends to oppose the group's third choice, as the Congress of the People refers to an event when the Freedom Charter - a document considered the cornerstone to the way the ANC governs - was signed in 1955.
"If they register their name with the IEC [Independent Electoral Commission], that's when the opposition will start," ANC spokesperson Ishmael Mnisi said.
The new party is led by former Defence Minister Mosiuoa Lekota and the former premier of Gauteng Province, Mbazima Shilowa.