Peronist Senator Miguel Ángel Pichetto will run for the presidency in 2019.
Pichetto announced his intentions at a special event at the Metro theatre in La Plata, the capital of Buenos Aires province, on Thursday evening.
He was joined by legislators, heavyweights from the Peronist movement and union leaders who support the current majority leader in the Senate.
"The debate of our times is about identity, about ideological proposals. While it seems difficult to imagine in 2018, our proposal has nothing to do with alliances with the Trotskyites or with those who think that by breaking things they can retake the power they once had. We are not the left", Pichetto charged.
"This government has had a period of very poor economic management, with the strong intervention of the State, which has impeded Argentina's growth", he said.
"Inflation, increased public spending in the last months of Cristina [Fernández] Kirchner's presidency and now Mauricio Macri, who has increased foreign debt, decreased spending power and devaluated [the peso] by 40 percent", he charged.
Peronist Party leadership hopefuls have had a difficult time transcending the polarisation that has ensured both Fernández de Kirchner and Macri enjoy solid voter bases of around 20 to 30 percent of the electorate.
Pichetto was joined in La Plata by lawmaker Diego Bossio; senators Carlos Caserio (Córdoba), Alfredo Luenzo (Chubut), Carlos Espínola (Corrientes), Rodolfo Urtubey (Salta); former Economy minister Miguel Peirano; former lawmakers Humberto Roggero, Eduardo Camaño, Raúl Ãlvarez Echague, Gilberto Alegre, Luis Basile, Damaso Larraburu, Liliana Gurdulich de Correa; and former senator Walter Barrionuevo.