(Adds quotes from unions, diplomat) By Saliou Samb CONAKRY, Feb 21 (Reuters) - Union leaders in Guinea insisted on Wednesday that President Lansana Conte must name a new, neutral prime minister before they would lift a general strike which has led the government to impose martial law. Strike leaders demand that Conte, a reclusive diabetic in his 70s, cede power. They relaunched their nationwide stoppage after Conte chose a close ally, Eugene Camara, as prime minister despite having agreed to name a consensus figure. "We can't hold discussions with someone who believes that Mr Camara is a consensus prime minister when his nomination caused the country to go up in flames," union negotiator Boubacar Biro Barry told Reuters during a break in talks with state officials. "More than 100 people have died because of this nomination. How are we supposed to have confidence in these circumstances," he said, before continuing the talks with religious leaders and the heads of the National Assembly and the Supreme Court. More than 120 people, mostly unarmed civilians, have been killed since the beginning of the year in clashes between security forces and protesters who have mounted demonstrations against Conte's 23-year rule. Conte decreed martial law in the West African state on Feb. 12 to halt the latest round of protests, which came after he named Camara -- a leading member of his ruling party -- as prime minister. The unions had demanded a premier with powers to hire and fire his own ministers, previously a role assumed by the president, and said the candidate should be free of the charges of corruption that have tainted recent administrations. WORRIED NEIGHBOURS Although the draconian martial law measures have restored calm to the world's leading bauxite exporter, analysts have warned the Guinean unrest could suck in and destabilise neighbouring states in one of Africa's most volatile regions. The presidents of neighbouring Liberia and Sierra Leone, both recovering from civil wars, flew to Guinea for talks with Conte on Tuesday fearing the political unrest may spill over into their own states. "If Sierra Leone and Liberia do not help quickly to resolve the situation in Guinea then the peace in those two countries will not be consolidated," Mohamed Sompare, Guinea's ambassador to Sierra Leone, told Reuters in Freetown on Wednesday. The unions rejected a proposal late on Tuesday that Camara remain in place for a three-month trial period, saying such a move would fly in the face of widespread public opposition. They are demanding a new prime minister and the lifting of martial law before they will end the strike, which has triggered food shortages in some parts of the capital and other towns around the country. Former colonial power France, the United States, the United Nations and the African Union have all called for a quick negotiated settlement to the crisis. (Additional reporting by Christo Johnson in Freetown)