Colombia's outgoing president, Gustavo Petro, has doubled down on allegations that June's presidential election was fraudulent, warning that the inauguration of his successor could lead the country toward civil war. Speaking to journalists in Bogotá on Monday, Petro — a former rebel fighter who became Colombia's first socialist president in 2022 — claimed that programmers had manipulated results from thousands of tally sheets after vote counts were transmitted to Colombia's national registrar, the agency responsible for organising elections. He accused electoral authorities of running an "obscure" process manipulated by foreign powers, including the United States and Israel, and said that metadata linked to scanned ballot records had never been made available for public review.

Electoral authorities and international observers have firmly rejected the allegations. Officials declared in late June that conservative lawyer Abelardo de la Espriella had defeated Petro's ally Iván Cepeda by roughly 250,000 votes, and electoral judges have since certified the result. De la Espriella, 48, is due to be sworn in on Friday — in a departure from tradition, the ceremony will be held in Cali, in southwestern Colombia, rather than in the capital Bogotá before Congress. Under Colombian law, Petro has no legal mechanism to block the transition. "We are facing a profound institutional problem," Petro said. "And it's the inauguration of an illegitimate president."

Petro went further by suggesting that de la Espriella intends to have him extradited to the United States on what he described as fabricated charges — a possibility he said could itself trigger civil conflict. "We know what a civil war in Colombia can look like," he said. He called on supporters in rural areas to form what he described as "liberation guards" to resist military detachments he claims are allied with local criminal groups. Cepeda has separately announced plans to lead protests against the incoming administration and said he will not recognise de la Espriella until he renounces his dual US citizenship, among other conditions.

Analysts warn that Petro's rhetoric carries serious risks in a country already scarred by decades of conflict among the military, drug-trafficking organisations, and armed rebel groups. Andrés Macías, a political science professor at Bogotá's Externado University, said the outgoing president's statements could "justify the use of weapons by civilians" in already volatile regions. Others note that the fraud narrative, even if unsubstantiated, risks deepening Colombia's political polarisation and undermining de la Espriella's standing with a portion of the electorate before he has even taken office.

Petro's final months in power were marked by sharp tensions with Washington. US President Donald Trump — who had publicly backed de la Espriella and whose campaign bore resemblance to the incoming Colombian leader's nationalist "Colombia First" platform — called Petro an "illegal drug leader" last October and threatened military action against the country in January. US prosecutors have also opened an inquiry into alleged links between Petro and drug traffickers during his 2022 campaign. Petro, aware that constitutional term limits bar him from seeking re-election, acknowledged on Monday that he has been warned to "behave well" once he leaves office, but said he could not in good conscience stay silent. "As a democrat," he said, "I cannot accept this electoral fraud."