BRUSSELS (AP) — A top Congo opposition figure who is barred from December's presidential election is warning that "chaos" will follow if the vote is not transparent and fair.

Former Congolese Vice President Jean-Pierre Bemba spoke to The Associated Press days before his sentencing at the International Criminal Court after being convicted of interfering with witnesses.

Congo's electoral commission rejected him as a candidate in the Dec. 23 election, calling the witness interference synonymous with corruption. Bemba accuses both the commission and the Constitutional Court, which last week upheld the decision, of being under "full control" of the government of President Joseph Kabila.

Bemba says he expects Congo's opposition to rally behind a joint candidate to challenge Kabila's preferred candidate but does not say who it should be: "I don't know, frankly."