DR Congo's former prime minister Matata Ponyo is one of the candidates who have pulled out of the race and announced that they will support Moïse Katumbi in the December 20 elections.
Campaigning began on November 19.
Katumbi, 58, is the candidate of the Ensemble pour la Republique party and a former governor of Katanga Province. He is one of the key challengers of incumbent President Felix Tshisekedi, who is seeking a second term.
Ponyo, who was DR Congo's premier from 2012 to 2016, announced he will back Katumbi - a decision he said came from a meeting five opposition leaders held in South Africa's capital, Pretoria.
Representatives of DR Congo's main opposition parties held talks earlier in Pretoria to decide on a potential joint candidate to challenge Tshisekedi in the December 20 general election.
Seth Kikuni, a candidate of the Piste pour l'Émergence party, declared his support for Katumbi on Monday, November 20, following Ponyo's announcement on Sunday.
In a statement, Kikuni rallied more opposition figures to support Katumbi as "the sole opposition candidate" to unseat Tshisekedi, who came to power in 2018.
Kikuni's announcement was followed by that of Franck Diongo, another candidate who pulled out of the race in favour of Katumbi.
In a joint statement, Ponyo, Kikuni and Diongo said a coalition led by Katumbi would be able to challenge Tshisekedi, whom they accuse of failing to deliver security to the Congolese people and perpetuating a multifaceted crisis that includes economic instability, violation of media freedoms, and failing diplomacy.
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Regime in place planning massive electoral fraud, systemic corruption
"It is clear that the regime in place, seeking to remain in power at all costs, is planning massive electoral fraud and systemic corruption," the statement reads in part.
"In order to thwart this macabre plan against the future of our nation, the urgency of a single candidacy from the Opposition emerges as the best strategy."
On November 3, the electoral commission approved a list of 25 candidates to face Tshisekedi in the polls. Other challengers include long-time opposition leader Martin Fayulu, who lost in 2018, and Dr Denis Mukwege.
Insecurity in eastern DR Congo is a campaign issue. The region, home to more than 200 armed groups, has been volatile for nearly three decades. In North Kivu Province, where a government-led coalition is fighting the M23 rebel group, hundreds of thousands of residents have been internally displaced while others fled the country.
In a mid-November interview with French media, Tshisekedi, who has been accused of exploiting the security crisis for political gains, implied that voters in parts of North Kivu might not be able to go to the polls.
Voter registration in the country's troubled east has been threatened by the security crisis, in which government-allied militias have wreaked havoc.
