Outgoing leader renews allegations that Colombia’s electoral authorities and international observers have rejected.

Colombia’s outgoing president, Gustavo Petro, has repeated allegations that June’s presidential election was rigged, rejecting the legitimacy of his right-wing successor, Abelardo de la Espriella.

Speaking before journalists in Bogota on Monday, the left-wing Petro claimed that programmers had altered thousands of tally sheets after counts were transmitted to the national election agency.

He alleged that the election was “obscure” and had been manipulated by foreign powers, and that metadata associated with vote tallies was not made available for review.

Colombia’s electoral authorities and international observers have rejected the fraud claims. Election officials declared in late June that de la Espriella, a conservative with a background in law, had defeated Petro’s ally Ivan Cepeda by 250,000 votes.

De la Espriella is due to be sworn in before Congress on Friday. Some analysts say the allegations could weaken his standing with some voters and deepen Colombia’s political polarisation.

Petro, a former rebel fighter who in 2022 became the country’s first socialist president, is barred from a second term by the Colombian constitution and has little ability to stop the transition of power after electoral judges certified the results.

“We are facing a profound institutional problem,” Petro said. “And it’s the inauguration of an illegitimate president.”

Feud with Washington

Petro’s final months in office were marked by repeated clashes with US President Donald Trump, whose administration has courted Latin America’s right and pressured its left-wing governments.

In October, Trump called Petro an “illegal drug leader” and announced an end to US payments to Colombia. Petro hit back by saying Trump was “rude and ignorant about Colombia”.

In January, after US forces abducted Venezuelan President Nicolas Maduro in Caracas, Trump was asked whether he would order a military operation against Colombia. The US president responded, “Sounds good to me.”

Weeks later, US prosecutors began a probe into potential links between Petro and drug traffickers in the course of his 2022 presidential campaign.

Petro said on Monday that he fears being “extracted” from Colombia once he becomes an opposition leader. He has called for protests and for rural areas to form “liberation guards”.

“I’ve been told to behave well,” Petro said. “But as a democrat, I cannot accept this electoral fraud.”

Andres Macias, a professor of political science at Externado University, said the call could “justify the use of weapons by civilians” in areas already impacted by conflicts between the military, drug traffickers and rebel groups.