Senegal's opposition coalition said Tuesday it would stage rallies over a threat to bar one of its leaders, Ousmane Sonko, from presidential elections after he was convicted in a defamation case.
Sonko was on Monday handed a six-month suspended term that could jeopardise his bid for the 2024 elections.
His possible elimination would significantly alter the contest, and could also lead to violence from his supporters.
Sonko claims the judiciary is being used to sideline him from the vote.
"The people have to mobilise to support Ousmane Sonko in this fight," Khalifa Sall, one of the coalition chiefs, told a press conference on Tuesday.
He joined other heads of the Yewwi Askan Wi alliance in urging followers to turn out in force for an already-scheduled rally due this Friday, and for another protest a week later, on May 19.
Senegal is traditionally a beacon of stability in troubled West Africa, but in recent years has been buffeted by turbulence that has at times turned deadly.
Sonko, 48, came third in the 2019 election against incumbent Macky Sall, and intends to stand again next year.
But his candidacy has been clouded by Monday's conviction, which saw an appeal court increase a sentence of two months suspended, handed down in March, for defaming Tourism Minister Mame Mbaye Niangtou.
The court also ordered Sonko to pay 200 million CFA francs (around $330,000) in damages to Niang.
The opposition figure has not issued any public statement since Monday.
Sonko is also facing trial later this month for alleged rape and death threats over a complaint filed by an employee at a beauty salon where he went for a massage.
He says he is the victim of a government plot to scupper his candidacy.
The government has denied the accusation.
In 2021, the rape charge against him helped trigger riots that left at least 12 people dead.
The presidential party accuses Sonko of seeking to paralyse the country and of drumming up anger on the streets in a bid to escape justice.
His appointments with the justice system are often sources of tension and near-paralysis of traffic in the capital Dakar, as he usually travels to court with a procession of sympathisers.
Political tensions have also been stoked by Sall's refusal to rule out running for a third term as president, a move his opponents say would be unconstitutional.
Khalifa Sall -- the former mayor of Dakar, who is not related to the head of state -- and former minister Karim Wade, the son of an ex-president, have also seen their political careers truncated by legal cases.
Both are prominent opponents of the current president.
Dethie Fall, another Yewwi Askan Wi figure, called for a march on May 19 against a "campaign to liquidate Ousmane Sonko".
He said that not to act "would be to let democracy be transformed into a monarchy and dictatorship by President Macky Sall, who has only one idea in mind, the third mandate".
The news of Sonko's conviction caused sporadic unrest on Monday in Dakar and elsewhere.
However, opposition calls for demonstrations have had a limited response in recent months.
Authorities have banned numerous rallies and deployed significant police resources.