Uganda’s presidential campaign season opened yesterday ahead of a vote due February 2016 pitting the incumbent against a longtime challenger and a sacked prime minister.

Eight candidates are running in the February 18 poll.

President Yoweri Museveni, in power since 1986, will face his stiffest opposition from Kizza Besigye, a three-time loser for the Forum for Democratic Change (FDC), and Amama Mbabazi, a former prime minister running as an independent candidate.

The Electoral Commission has urged candidates to conduct peaceful campaigns and comply with the law, including a dusk curfew on rallies and campaigning to end two days before the polls.

Pressure group Human Rights Watch (HRW) called for free and fair elections.

"This campaign period is a critical opportunity to avoid the repression, violence, police brutality, and recriminations of past campaigns,” said Maria Burnett, senior Africa researcher, in a statement.

Other candidates are university professor Venansius Baryamureeba, Abed Bwanika of the People's Development Party – who vowed to rehabilitate homosexuals if elected – evangelical pastor Joseph Mabirizi, retired general Benon Biraaro and lawyer Faith Kyalya, the only female candidate.

At the head of the ruling National Resistance Movement (NRM) party, Museveni is widely-expected to win another five-year term with opposition leaders so far failing to field a joint candidate as promised.

Besigye and Mbabazi have agreed to field a joint candidate in a bid to unify opposition to Museveni, under The Democratic Alliance (TDA) party.

But efforts so far to select the candidate have collapsed, as all want to be leader.