Argentines are voting Sunday in a primary that will be the deciding factor ahead of a general election in October, The Associated Press reports.

The results of the primary elections will determine who will become the presidential candidate from the main opposition coalition, in which the Mayor of Buenos Aires, Horacio Rodríguez Larreta, is pitted against former Minister of Security Patricia Bullrich.

The contender to come out on top will almost certainly run against Economy Minister Sergio Massa, the candidate of the ruling coalition. Center-left President Alberto Fernández has opted not to seek reelection due to his extremely low approval ratings amidst annual inflation surpassing 100%, an increase in poverty, and swift currency devaluation.