Joshua Osih, vice-president of the main opposition Social Democratic Front (SDF), said evidence of double-voting and a lack of ballot papers in some polling stations meant the results, which are due in coming days, could not be credible.
“It is evident that this election will not give any winner any legitimacy. That is why we are filing a case with the Supreme Court for the election to be simply annulled,” Osih told Reuters by telephone.
Incumbent Paul Biya, in power in the central African state for 29 years, is widely expected to be re-elected in the single-round vote, which he contested against more than 20 rivals from the splintered opposition.
Biya, 78, has acknowledged there may have been “imperfections” in the staging of Sunday’s election, but denied there had been fraud.
He was able to run for re-election only because he scrapped presidential term limits in 2008 — a move which, added to street anger over food prices, provoked riots in which more than 100 people died.
Albert Dzongang, who ran as a candidate for the smaller opposition party Dynamique pour la Renaissance Nationale but was unable to vote because he could not get his voter card, told Reuters: “What happened on Sunday should simply be declared null and void.”
Another opposition candidate, Anicet Ekane of the MANIDEM party, said his lawyers were also preparing to file a request with the Supreme Court for the vote to be annulled.
Cameroon’s economy has considerable potential but has not grown as fast as expected in recent years