By Richard Lough and Juliana Castilla
BUENOS AIRES (Reuters) - Argentina's main opposition party suffered a split on Wednesday after a dozen of its lawmakers quit, party leaders said, handing a boost to newly-elected President Mauricio Macri's hopes of pushing his legislative agenda through Congress.
The rupture within former President Cristina Fernandez's Front for Victory (FPV) party was confirmed by party chiefs after a day-long meeting in the capital Buenos Aires. The divide laid bare the internal battle over how to recover from November's election defeat.
Hector Recalde, leader of the FPV in the lower house, told reporters "more or less a dozen" legislators had left the party. That would leave it with 83 seats in the 257 seat chamber, meaning Macri's "Let's Change" alliance, which includes his PRO party, the Radical Party and several independents, is set to become the largest minority block in Congress.
Emerging from the meeting, some FPV party faithful struggled to contain their annoyance.
"This is bad news for the Argentine people," said FPV lawmaker Juliana Di Tullio. "I don't know what they represent anymore, but of course they spoke to the PRO."
The split means that Macri now no longer needs to negotiate with the FPV to secure a majority in Congress's lower house.
Instead he can approach parliamentarians allied to defeated presidential candidate Sergio Massa as well as the new block of dissident Peronists who analysts expect will remain in opposition.
Both groups are viewed as more moderate than the Fernandez loyalists inside the FPV. Massa accompanied Macri to the World Economic Forum in Davos where the pair put on a united front before multinational chief executives.
The shift in Congress could prove key when it returns from recess in March. Perhaps Macri's biggest challenge this year will be securing Congressional approval for any eventual deal with U.S. creditors suing the country over unpaid debt.
Fernandez, whose eight years in power were deeply divisive, refused to negotiate with the investors, calling them "vultures".
The rupture underlines internal rifts within the FPV, the main Peronist party, over how to rebuild power after the shell-shock of November's presidential election defeat, said political analyst Ignacio Labaqui at Medley Global Advisors.
"There is a faction within Peronism that wants a more constructive, less aggressive approach toward the administration, whereas Fernandez loyalists advocate a more hardlined approach," said Labaqui.
There was no immediate comment from any of the defecting lawmakers.