Former Argentine president Cristina Fernandez de Kirchner has announced that she will stand as a vice-presidential candidate in national elections later this year.
It means that ex-cabinet chief Alberto Fernandez will run as the Justicialist party presidential candidate.
Ms Fernandez was tipped to be the main challenger to President Mauricio Macri.
Despite facing charges of corruption, her popularity has grown as Argentines live through austerity measures.
The population will head to the polls in October, with Mr Macri increasingly under fire amid a biting recession
Ms Fernandez, a controversial left-leaning populist, said in a video posted on social media on Saturday that she would run for the deputy position.
"I have asked Alberto Fernandez to lead a team that includes both of us, him as the presidential candidate and me as candidate for the vice position," she said in a nearly 13-minute long video on her official Twitter account.
Ms Fernandez was perceived as the biggest threat to Mr Macri, although many remain wary of turning back to the leftist who brought in currency controls and raised taxes on farm exports.
Mr Fernandez, meanwhile, is little known outside of Argentina.
He served as chief of staff for former President Nestor Kirchner, Cristina Fernandez's late husband, and for a few months during her first administration.