DR Congo's main opposition party on Monday rejected a deal agreed by its leader just a day earlier to select a single opposition candidate for upcoming presidential elections.
After hundreds of activists protested, Mr Jean-Marc Kabund, the secretary general of the Union for Democracy and Social Progress (UDPS), announced "the grassroots want (party leader) Felix Tshisekedi to withdraw" from the deal, and set a 48-hour deadline for him to do so.
Seven opposition leaders, meeting in Geneva on Sunday, picked the little-known Martin Fayulu as their joint candidate for the December 23 ballot to succeed President Joseph Kabila, who has been in power for 18 years.
The choice of Mr Fayulu, a 61-year-old former oil executive, was a surprise as Mr Tshisekedi, who heads the UDPS -- for years the country's main opposition party -- had widely been seen as the front-runner.
Mr Kabund said UDPS activists opposed the Geneva agreement as "they consider him (Tshisekedi) to be the candidate for the presidency."
Mr Fayulu will run at the head of a new opposition coalition called Lamuka -- which means "wake up" in both Lingala and Swahili.
He will stand against Mr Emmanuel Ramazani Shadary, a hardliner and former interior minister backed by President Kabila.
The vote is crucial for the Democratic Republic of Congo, which has never experienced a peaceful transition of power since it gained independence from Belgium in 1960.
Mr Tshisekedi, who has a home in Belgium, has not yet returned to Kinshasa.