Denis Sassou Nguesso, the president of Republic of the Congo, held his final campaign rally on Friday in the capital, Brazzaville, ahead of Sunday’s presidential election, as supporters gathered to show their backing for the veteran leader seeking to extend his decades-long rule.

At 82, Sassou Nguesso is widely viewed as the frontrunner in the vote after more than 40 years in power. Analysts say the election is likely to take place amid limited opposition participation and could see historically low voter turnout in the oil-rich but economically struggling Central African nation.

Sassou Nguesso is among Africa’s longest-serving leaders, alongside Teodoro Obiang Nguema Mbasogo of Equatorial Guinea and Paul Biya of Cameroon.

Some voters in Brazzaville have expressed skepticism about the election’s outcome. “Honestly, I don’t see the point of voting on March 15. Whether I vote or not, we’ll have the same winner,” said Cyril Massamba, a resident of the capital.

A former military officer, Sassou Nguesso first came to power in 1979, ruling under a one-party system until 1992, when he lost the country’s first multiparty election to former prime minister Pascal Lissouba. He returned to power in 1997 following a civil war that ousted Lissouba and has remained in office ever since.

Constitutional changes that removed presidential term limits and age restrictions have enabled Sassou Nguesso to run for additional terms, despite recurring allegations of corruption and criticism from political opponents.

Six candidates are formally challenging the incumbent in Sunday’s vote, but few possess the financial or political backing to compete with the ruling Congolese Labour Party (PCT).

Opposition forces remain fragmented, and their inability to unite behind a single candidate has weakened their chances of mounting a serious challenge.

Two of the country’s main opposition parties have opted to boycott the election, arguing that conditions for a free and transparent vote are not in place. One party has instead urged supporters to vote “according to their conscience.”

Opposition figure and former minister Clément Mierassa has accused the government of controlling the electoral process, claiming that candidates running against Sassou Nguesso are merely symbolic challengers.

Meanwhile, two prominent opposition figures who contested the disputed 2016 election—Jean-Marie Michel Mokoko and André Okombi Salissa—remain in prison, serving 20-year sentences after being convicted of “endangering state security.”