Thousands of Peruvians have marched through Lima to vent their outrage over a pardon for the jailed former president Alberto Fujimori, in the biggest protest since the decision was announced.



The public opprobrium was directed at Peru’s president, Pedro Pablo Kuczynski, who granted the pardon on health grounds on Christmas Eve to lift the 25-year sentence, Fujimori, 79, had been serving for corruption and authorising death squad killings.

Public indignation threatens to push Kuczynski’s beleaguered government into a political crisis as he reshuffles his cabinet and seeks to forge a new alliance with the majority opposition party led by Fujimori’s daughter Keiko.



“The president has lost all legitimacy,” said Maria Isabel Cedano, a feminist campaigner who supported Kuczynski, known as PPK, in Peru’s 2016 presidential runoff to prevent a victory for Keiko Fujimori. “He has betrayed us. He should resign and convene new elections.”

Amid the face-painted drummers, workers’ unions, students and feminist collectives wearing traditional Andean embroidered skirts, Kuczynski’s image was a new addition to the rubber-faced puppet caricatures worn by actors waving bundles of banknotes in the burlesque parade usually reserved for Fujimori and other former leaders tainted with corruption.



Marchers wore headbands reading “The pardon is an insult” and carried placards saying “Justice cannot be negotiated” as they chanted “Out, out PPK.”



People holding pictures of victims of the guerrilla conflict march against President Kuczynski’s pardon for former president Alberto Fujimori in Lima. Photograph: Mariana Bazo/Reuters

Alberto Fujimori, whose authoritarian leadership in the 1990s left an indelible mark on the country, continues to cast a long shadow over modern Peru. His supporters credit him with stamping out the Maoist Shining Path movement and responsibility for Peru’s economic success while others consider him a corrupt and iron-fisted dictator.



Speaking from a hospital bed on Tuesday, Fujimori asked for forgiveness from the Peruvians he said he had “let down”. He thanked Kuczynski for the pardon and pledged to back the president’s call for national reconciliation.



“It was a taunt,” said Rosa Rojas Borda, who lost her eight-year-old son Javier and husband Manuel, in the 1992 Barrios Altos massacre, one of two carried out by a military death squad Fujimori was convicted of having created.



“He should ask for forgiveness from the relatives of those he had killed. They have a first and last name,” she told the Guardian as she strode at the front of the march with other family members carrying placards bearing black and white photos of their loved ones who were killed in the early 1990s.



“PPK has never invited us – the families of the victims – to visit him, as he has Keiko and Kenji. We’ve asked him three times,” said Carmen Oyague, 70, whose daughter, Dora Oyague Fierro, was one of nine students and a university professor who were abducted and killed in 1992.



Her niece, Carolina Oyague, 36, said: “You can’t reconcile the country by decree,” referring to a message on Tuesday in which the 79-year-old leader asked young people to leave aside “negative emotions” and “turn the page”.



Human rights lawyers in Peru say there are legal grounds to challenge the pardon because it was a political and not a humanitarian decision.



Public indignation threatens to push Pedro Pablo Kuczynski s already beleaguered government into a political crisis. Photograph: Martin Mejia/AP

Carlos Rivera, a lawyer at the Legal Defence Institute, said Kuczynski issued the pardon as a part of a deal to avoid impeachment on corruption allegations last week. The president has denied wrongdoing.



Human rights experts at the UN called the pardon an appalling “slap in the face” to the victims of human rights abuses, adding it was granted on “politically motivated grounds” and was a “major setback for the rule of law in Peru”.



Fujimori’s “guilt is not in question” and he did “not meet the legal requirements for a pardon”, they concluded.

The Inter-American Commission on Human Rights expressed “deep concern” over the pardon.

“The pardon is a major reversal in the consolidation of Peru’s democracy,” says Paulo Drinot, a senior lecturer in Latin American History at University College London. “PPK has undermined the rule of law for his own political survival. He will go down as one of the most pusillanimous and unprincipled presidents in Peruvian history.

“With the pardon, he may also have created the conditions for a much more fractious and openly confrontational period of Peruvian politics,” he said.

