By Elias Biryabarema
KAMPALA (Reuters) - Uganda's two main opposition presidential hopefuls are in talks about fielding a single candidate to challenge Yoweri Museveni in next year's election, aides said on Friday.
Amama Mbabazi, a former prime minister and one-time ally of Museveni, and Kizza Besigye, who has been defeated in three previous polls, each boast a solid support base but may struggle to pose a real challenge if their votes are split, experts say.
Rebel-turned-president Museveni, 71, who has ruled since 1986, could be facing his toughest race yet, particularly if his opponents unite. But he has proved adept at keeping the opposition fractured in the past, experts say.
Josephine Mayanja-Nkangi, spokeswoman for Mbabazi, told Reuters that Mbabazi and Besigye had held consultations in London in recent days to agree on "a single coalition with one presidential candidate" and other issues.
Such a tactic was discussed by the opposition in past elections, but no agreement reached.
"At this stage we have only agreed on a set of objectives on which we're holding talks," Mayanja-Nkangi said.
Mbabazi, who fell out with Museveni and was sacked as prime minister last year, is running as an independent candidate.
Besigye's Forum for Democratic Change (FDC) and a number of smaller parties formed a coalition this year, pledging to field a single candidate. But, as in past votes, the alliance has failed to agree on a joint candidate.
Francis Mwijukye, a senior FDC official, said there were talks with Mbabazi with agreement on the need to oust Museveni, but no concrete deal had yet been reached.
"On the details of how we intend to cooperate and to what level and extent, (there is) no consensus yet," he said.
Museveni won plaudits for restoring strong economic growth and a measure of political stability after years of turmoil in Uganda, a nation that relies heavily on agricultural exports and aid inflows and wants to develop newly-discovered oil reserves.
After years in office, his critics accuse him of failing to halt corruption and of using his security forces to stifle opponents, a charge officials deny. Western donors also show increasing frustration with his extended grip on power.
Both Besigye and Mbabazi have been briefly detained in the run-up to the vote, expected in February or March. Their supporters say the detentions were politically motivated.
Police said the two men and their supporters were planning illegal campaigning before either had been formally approved as a candidate, which is expected in early November.
(Editing by Edmund Blair and Andrew Roche)