President Alberto Fernandez faces a nervous 24 hours as Argentines head to the polls in mid-term parliamentary elections on Sunday that could see his party lose its Senate majority.
Nearly half the lower house Chamber of Deputies seats are up for grabs, as well as a third of the Senate members in the mandatory vote for 34.3 million people.
Fernandez's Frente de Todos (Everyone's Front) party is already a minority in the lower house and analysts believe it risks losing its Senate majority.
In September, the Frente suffered a bruising defeat in primaries, picking up just 33% of the vote compared to 37% for Fernandez's predecessor Mauricio Macri's Juntos por el Cambio (Together for Change) opposition group.
"If the results of the PASO (September's primary) are repeated, the ruling party could lose its majority in the Senate," said political analyst Rosendo Fraga of the New Majority think tank.
Fernandez's government has been hard-hit by growing public discontent.
The country has been in recession since 2018, with GDP dropping 9.9% last year due to the coronavirus pandemic.
Argentina has one of the world's highest inflation rates, at 40% so far this year, and a poverty rate of 42% for a population of 45 million.
The primaries setback unleashed a political crisis pitting Fernandez against his deputy president and coalition partner Cristina Kirchner, who pressured her boss into a cabinet reshuffle in the hopes it would help appease an increasingly-frustrated electorate.
If the Frente loses its Senate majority, the opposition "will most probably use" its legislative blocking power, said analyst Gabriel Puricelli of the University of Buenos Aires.
The Frente would then be forced to negotiate and make concessions if it wants to pass laws or make key appointments, including to the judiciary.
Possible wild card candidate
Since the primaries, the government has been in damage limitation mode, announcing last month a deal with the private sector to freeze prices on more than 1,500 basic goods, following street protests demanding greater food subsidies.
It has also increased the minimum wage and family allowances.
The government has rallied its supporters following months of pandemic lockdowns that kept them hidden away.
Pro-government trade unions and social organizations announced they will march in support of Fernandez on Wednesday regardless of Sunday's results.
Many eyes will be on Buenos Aires province, a traditional bastion of Peronists including Fernandez's party, but where Macri's Juntos made great strides in September.
There is a potential spoiler in the field, though, in the form of the provocative Javier Milei -- an ultra-liberal anti-establishment economist who is pushing for a seat in the Chamber of Deputies for the city of Buenos Aires.
Milei has both the center-right opposition as well as the center-left government worried, both of whom he has criticized.
His rise has drawn comparisons to successful populists like Donald Trump in the United States or Brazil President Jair Bolsonaro.
Milei has managed to attract support from all social classes, although some analysts point out most tend to be men aged 18-40.
He has caught Macri's attention, though.
"The ideas Milei has been espousing, I have always expressed them," said the former president recently.
Polls will close at 6:00 pm (2100 GMT) on Sunday the with first results expected around three hours later.
