By Marco Aquino
LIMA, June 18 (Reuters) - Right-wing candidate Keiko Fujimori was on track on Thursday to win Peru's presidency by a narrow but growing margin, with only 0.6% of votes left to be reviewed, while leftist rival Roberto Sanchez called for protests after alleging irregularities at the electoral authority.
Fujimori, making her fourth bid for the presidency, held a lead of 39,115 votes in a count that has kept Peru on edge since the June 7 runoff.
Challenged ballots still pending review represented about 140,000 votes as of early Thursday. Around 60% of those votes came from Lima and from Peruvians living abroad, where Fujimori has drawn stronger support than her rival.
"These are areas where Keiko Fujimori should have an advantage," said Gonzalo Marquez, head of data consultancy Caleidos. "So there is no possibility, let's say, that the result will change."
According to the latest overall tally from the Peruvian elections office, the daughter of late former President Alberto Fujimori had 50.11% of valid votes, compared with 49.89% for Sanchez, with 99.38% of ballots counted.
Fujimori, who could become the first woman elected directly to Peru's presidency, has lost three previous runoffs. In the most recent, in 2021, she was defeated by leftist Pedro Castillo by just 44,200 votes.
As the slow review and recount of challenged ballots continued, Sanchez's party filed legal appeals seeking to void votes favoring Fujimori and called for protests in Lima on Friday.
"This election isn't over yet," Sanchez said during a press conference at his party's headquarters in Lima on Thursday, where he also criticized the electoral authority. "We're marching on (Friday) and I'll be there at the front."
Peru's National Electoral Jury (JNE) will evaluate Sanchez's legal challenges on Friday.
Election observer missions from the Organization of American States and the European Union said separately that the vote had proceeded normally and urged candidates and the country to await the official result.
(Reporting by Marco Aquino; Editing by Emelia Sithole-Matarise and Mark Porter)
