Congo's Constitutional Court on Tuesday certified the re-election of longtime leader Denis Sassou-Nguesso, two weeks after provisional results gave him a widely expected landslide victory in the central African country.

Rejecting an appeal by the opposition, court president Auguste Iloki said Sassou-Nguesso, 77, is "declared elected" with 88.4 percent of the vote.

The March 21 election was boycotted by the main opposition and overshadowed by the death from Covid of Sassou-Nguesso's only major rival, Guy-Brice Parfait Kolelas, 61, who garnered 7.84 percent of the vote.

Sassou-Nguesso campaigned as the defender of Congo's youth -- the average age of the country's five million people is 19 -- and outlined plans to develop agriculture in order to ease dependence on food imports and diversify the economy of the oil-rich country.

A campaign poster of Congo's re-elected President Denis Sassou-Nguesso is pictured outside outside the headquarters of the ruling Congolese Labor Party in Brazzaville on March 23, 2021
A campaign poster of Congo's re-elected President Denis Sassou-Nguesso is pictured outside outside the headquarters of the ruling Congolese Labor Party in Brazzaville on March 23, 2021 AFP / ALEXIS HUGUET

One of the world's longest serving leaders, Sassou-Nguesso has been in power for an accumulated 36 years, first taking the helm in 1979.

The former paratrooper's election to another five-year term marks his fourth win since 2002.

Critics have accused him of authoritarian rule and turning a blind eye to corruption, poverty and inequality despite the country's oil wealth.

Kolelas, the son of a former prime minister who was a leading government critic, died aboard a medical plane that flew him to Paris on polling day.

Coronavirus