South Africa's ruling party has said President Jacob Zuma must leave office.
Ace Magashule, secretary-general of the African National Congress (ANC), said the party's national executive committee had decided to "recall" Mr Zuma, who has been discredited by a number of corruption scandals.
Mr Magashule said the president had previously agreed to resign, but wanted to stay in office for several more months, a condition the party committee rejected.
If Mr Zuma refuses to co-operate, the matter could go to parliament for a vote on a motion of no confidence.
The continuing lack of a resolution to the country's political limbo indicated that the president was spurning the demands of many former supporters and possibly holding out for concessions in exchange for his resignation.
The impasse highlighted the disarray within the party that was previously the main movement against white minority rule and has led South Africa since the end of apartheid in 1994.
The ANC once commanded moral stature as the party of Nelson Mandela, but corruption scandals linked to Mr Zuma have cut into its popularity ahead of national elections next year.
An opposition-backed motion of no confidence had been scheduled for February 22, but its sponsors want the vote to be moved to this week.
Mr Zuma has survived similar motions against him in the past, but many ruling party members now see him as a political liability and would probably vote against him.
Mr Zuma, who took office in 2009 and is in his second five-year term, has asked for state security for his family, payment of legal fees and a few more months in office in exchange for quitting, said South African media, citing unidentified ANC sources.
Deputy President Cyril Ramaphosa, Mr Zuma's expected successor, has held private talks with the president on a power transition, angering opposition parties who described the process as an affront to South African democracy.
Last week, Mr Ramaphosa promised a "speedy resolution" to the discussions, but the protracted stand-off has raised questions about the political clout of the man poised to lead the country.
South Africa's leading court ruled that Mr Zuma violated the constitution following an investigation of multimillion-dollar upgrades to his private home that were paid by the state; a judicial commission is about to start a probe of alleged looting of state enterprises by some of his associates; and prosecutors are expected to announce soon whether they will reinstate corruption charges tied to an arms deal two decades ago.
He denies wrongdoing.