Ugandan opposition leader prepares fourth presidential challenge

Kizza Besigye attends an interview with Reuters at his home in Kasangati near Kampala, January 13, 2012. REUTERS/James Akena

KAMPALA (Reuters) - Veteran Ugandan politician Kizza Besigye will seek the opposition's nomination to challenge Yoweri Museveni in presidential elections next year, that could provide the toughest test of the incumbent's almost three decades in power.

The opposition have vowed to put aside differences and impose a single candidate to run against Museveni, who is widely expected to win should he seek another term.