DAKAR, Senegal (AP) — Senegal’s highest election authority has excluded two top opposition leaders from the final list of candidates for the West African nation’s presidential election next month. The party of the main challenger called the move a “dangerous precedent” on Sunday.

The list published Saturday by Senegal’s Constitutional Council named 20 candidates, including Prime Minister Amadou Ba, who has the backing of outgoing President Macky Sall and is seen as a major contender.

Opposition leader Ousmane Sonko, who finished third in the country’s 2019 presidential election,was disqualified from the ballot because he faces a six-month suspended sentence following his conviction for defamation, the Constitutional Council said.

“This conviction renders him ineligible for a period of five years,” the council said.

Sonko, who currently is imprisoned on a different charge, was widely seen as the politician with the best chance of defeating Sall’s ruling party. His PASTEF party, which authorities dissolved last year, called Sonko’s disqualification “the most dangerous precedent in the political history of Senegal.”

The council also deemed Karim Wade, another opposition leader and the son of former Senegalese President Abdoulaye Wade, as ineligible for the ballot. It said Wade had dual citizenship at the time he formally declared his presidential candidacy, although he had renounced his French nationality three days earlier.

“The recent decision of the Constitutional Council is scandalous, it is a blatant attack on democracy (and) violates my fundamental right to participate in the presidential election,” Wade wrote in a post on X, formerly known as Twitter.

The Constitutional Council’s decision could further complicate preparations for the Feb. 25 election. Opposition supporters accused Sall’s government last year of clamping down on their activities, and some protests in support of Sonko turned deadly.