Former Argentine President Cristina Fernández de Kirchner intends to run for the office again this year, Diasporpress.az citing Reuters.
The election run, if confirmed, would make Fernández the first and most high-profile challenger to Macri, who is expected to run for a second term but whose leadership has faced heavy criticism after rampant inflation last year and a falling economy hit voters hard.
A Macri versus Fernández battle would likely dominate the election process in what will be a major crossroads for Argentina's economic and political future: a choice between Macri's IMF-backed economic reforms or a return to Peronism.
The Presidential election will be held in Argentina in October.
Fernandez - who led the country from 2007 through 2015 and is now a senator - is Macri's arch political rival and is among his main critics from within the country's Peronist movement.
Fernandez was indicted last year on charges that her administration accepted bribes from construction companies in exchange for public works contracts.
Fernandez has denied the charges and said she never received any illicit money. As a senator, she has immunity from arrest, but not from prosecution.