Guinea-Bissau President Jose Mario Vaz named a new prime minister on Thursday in a bid to end a power vacuum after he dismissed the previous premier Domingos Simoes Pereira last week, according to a decree read on state radio.
The appointment of Baciro Dja, formerly minister of presidential affairs, was condemned by some members of the ruling PAIGC who called for a public protest in the coastal capital of the small West African country.
Pereira remains head of the PAIGC, a role which would ordinarily also grant him the title of prime minister.
However, tensions have grown between the president and his former political rival Pereira, fed by overlapping duties in Guinea-Bissau's semi-presidential system.
"The leadership of the party is now holding a meeting and we will make an announcement at the end," Pereira told Reuters by telephone.
The former Portuguese colony has a long history of political instability and has suffered nine coups or attempted coups since 1980, the most recent of which took place in 2012. Elections last year returned the country to democratic rule and unfroze international aid.
Drug traffickers have taken advantage of the chaos and used the country as a transit point for smuggling cocaine between South America and Europe.