Supporters of President Joseph Kabila on Thursday denounced alleged cheating in an opinion poll that placed two opposition leaders well ahead before a presidential election due on December 23.Results of the national poll, released on Tuesday, tipped Felix Tshisekedi, president of the main, historic opposition party, and former national assembly speaker Vital Kamerhe to win.The poll, jointly conducted by BERCI consulting, a Congolese organisation, and the Congo Research Group at New York University, put Kabila's favourite Emmanuel Ramazani Shadary in third place."We're denouncing bumbling manipulation," government minister Felix Kabange, the spokesperson for the Common Front for the Congo (FCC) and the pro-Kabila coalition, told AFP."Behind the result of this BERCI poll, you can see the hand of Olivier Kamitatu," Kabange added, targeting one of the founders of the consulting group and spokesperson for powerful businessman Moise Katumbi, a heavyweight barred from the election."BERCI and the CRG are trying ineptly to discredit Emmanuel Ramazani Shadary when on the ground, the very opposite has been observed by neutral and rigorous people," Kabange said.Shadary, a hardline former interior minister, was named candidate of the presidential majority after Kabila finally agreed to step down after 17 years in power and the postponement of the election from late 2016."This is ridiculous! I left BERCI almost 20 years ago. I don't know anything about what is happening in BERCI," responded Kamitatu, reached by telephone in Belgium, the former colonial power in the vast central African country.The poll was carried out "from September 29 to October 15, 2018, among 1 179 people aged 18 and over, spread across the 26 provinces of the country," according to the organisers."The interviews were recorded on electronic tablets with the help of the Open Data Kit," the team wrote, referring to an open-source data-management software community suited to environments that are short on resources.Twenty-one candidates are standing in the presidential vote, which will be combined with a parliamentary election and elections to the provincial assemblies.The votes come after more than a year of political tension across a mineral-rich nation that is also troubled in the east by armed ethnic rivalries and mass population displacement. The security forces have cracked down violently during street protests against Kabila's hold on power.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.