Russian President Vladimir Putin has maintained his hold on power for more than two decades. Authorities overseeing the presidential election next month are weighing whether to keep one of his critics off the ballot.
Boris Nadezhdin is a former member of the lower house of parliament. He has attracted attention for his opposition to the war in Ukraine. He collected the 100,000 signatures required and handed them over last Wednesday to the Central Election Commission.
On Monday, commission officials said they had found 15 percent of the signatures to be invalid, three times what they allow. They said some of those listed as supporters are dead. They will make their final ruling on Wednesday on whether to disqualify Nadezhdin, something they have done to other challengers.
Nadezhdin and his team said they would collect signatures right up to the deadline. They said they will appeal to the Supreme Court if the commission refuses to register him as a candidate.