Niger's constitutional court has approved 15 candidates for next month's presidential election, the interior ministry announced on Saturday, including imprisoned opposition figure Hama Amadou.
Incumbent Mahamadou Issoufou, elected in 2011, is seeking another term and will also be up against chief opposition leader Seini Oumarou, former president Mahamane Ousmane and ex-planning minister Amadou Boubacar Cisse, among others.
At the start of the week the interior ministry put forward 16 names of potential candidates to contest the February 21 election.
Of these only Abdoul-Karim Bakasso, the leader of a minor party, was deemed "ineligible" by the court, Interior Minister Hassoumi Massaoudou told reporters.
His bid was rejected due to "the lack of a medical certificate," said opposition spokesman Ousseini Salatou.
Amadou, seen as one of Issoufou's strongest opponents, has been in prison since November 14, 2015 over allegations he was involved in baby trafficking.
The former prime minister and national assembly president fled the county in August 2014 to escape charges in the matter but was arrested after he returned last November.
Amadou has proclaimed his innocence and considers the legal process against him to be "political".
A legal decision on his latest demand to be freed provisionally is expected Monday.
Former agriculture minister Abdou Labo, who was also implicated in the affair and is currently out on bail, is also on the list of approved presidential candidates.
- 'Deteriorating political climate' -
The political climate in the arid Sahel state has been tense since Amadou joined the opposition in 2013.
The election commission late last month announced that the first round of voting would be held on February 21, followed by a run-off on March 20 if necessary.
The opposition has rejected the timeline, saying there had been no consensus on the dates.
The government on Saturday banned a march that had been planned by the opposition the following day to rally against what it called the "arbitrary arrests" of some of its supporters and to call for "transparent elections".
According to opposition spokesman Salatou, the authorities said the march posed "a risk to public order".
Niger's influential tribal chiefs on Friday expressed their concern at the "deteriorating political climate".
Last month President Issoufou said the government had foiled a coup plot, a claim rubbished by presidential hopeful Boubacar Cisse.
Politicking aside, whoever wins the race for the top job will have to tackle the pressing issue of Boko Haram attacks from neighbouring Nigeria.
Boko Haram, which has pledged allegiance to the Islamic State group, has stepped up attacks on areas of Niger, Chad and Cameroon that border Nigeria while also continuing a devastating campaign of suicide and shooting attacks on home soil.
Electoral campaigning will get under way in Niger on January 30 for both presidential and legislative ballots.