President Jacob Zuma of South Africa has called for unity in the governing party and condemned leadership squabbles in the ANC.
Amid reports of growing unease at his leadership, he called for a return to "revolutionary discipline" in the ANC.
In a speech to party members in Durban, Mr Zuma said there were what he described as worrying tendencies that were becoming entrenched in the party.
He said"individuals" were "seeking to put themselves forward for political gain."
The BBC reports the ANC's relationship with its union allies was hit by a recent nationwide strike by some one million civil servants.
But Mr Zuma denied that the ANC's partnership with unions and the left was under threat, saying predictions of the imminent break-up were "a waste of time and ink".
However, he warned them that the ANC is the "leader of the alliance".
Cosatu trade union federation head Zwelenzima Vavi recently said the alliance with the ANC was "dysfunctional".
Mr Zuma also took a stiff line on ANC members who publicly condemned the party, saying they would face discipline.
"We have no choice but to reintroduce revolutionary discipline - junior structures must respect senior structures of the ANC," he said.
However, he said the party was more stable than seemed possible three years ago when it was deeply divided between his supporters and those of his predecessor, Thabo Mbeki.
Mr Zuma attacked what he called "worrying tendencies in the party, and individuals" he said "were seeking to put themselves forward for political gain."
The BBC reports this was believed to have been directed at ANC youth wing leader Julius Malema, who recently raised questions about President's Zuma's authority to lead and who is privately reluctant to back him for a second term.