Argentines head to the polls on Sunday to vote in mid-term elections expected to deal a severe blow to the current government and dent possible reelection plans of President Cristina Fernández de Kirchner.

The 60-year-old leader, recovering from brain surgery earlier in the month and reportedly not following events in the media, has been notably absent as she complies with her doctors’ wishes for strict rest.

The elections will determine the makeup of Congress — half the seats in the Chamber of Deputies and a third in the upper chamber Senate are up for grabs — and could turn out badly for the government if August’s primaries are an indication. August’s ballot essentially acted as a test-run for Sunday, with the government’s Victory Front coalition winning just 26 per cent of the national vote.

“It’s likely that the government will lose its absolute majority in both houses on Sunday,” said Ignacio Labaqui, professor of Latin American politics at the Argentine Catholic University in Buenos Aires. “It will be more difficult to pass legislation than in the last couple of years — but we’re, of course, not going to see something like the U.S. shutdown.’’

These mid-term elections have become a litmus test for the durability of Kirchnerismo, the “national and popular project” that became government doctrine when Fernández de Kirchner’s now-deceased husband Néstor Kirchner assumed the presidency in 2003 and continued when the mantle was passed to her in 2007.

The main challenge to its enduring legacy is in Buenos Aires Province, Argentina’s agricultural heartland and home to a third of the electorate. Heading the polls for national deputy there is Sergio Massa, mayor of Tigre and a former government ally who broke away to form his own Renovation Front earlier this year. Recently published figures from Buenos Aires-based pollster Poliarquía give him 41.2 per cent of the vote, ahead of the officially nominated candidate, Martín Insaurralde, who was trailing with 33.2 per cent.

Massa cut a confident figure on Thursday when he addressed voters in Tigre during his campaign-closing speech. “Starting Oct. 28, we will surely have an enormous responsibility,” he said.

The center-right, business-friendly candidate has become a focal point for dissatisfaction with the government, including perceived spiraling crime levels, currency controls and an inflation rate that private economists estimate to be around 25 per cent.

Massa has promised to get tough on crime, even bringing in former New York Mayor Rudy Giuliani to make a speech about his “zero tolerance” record at a campaign rally earlier in the month. He also tried to cut a conciliatory figure on Thursday, saying he wanted to bring together “all political sectors.”

“The government was defeated in the primaries and more than anything else in Buenos Aires Province,” said Facundo Martínez, head economist at M&S Consultants in Buenos Aires. “Massa is a candidate with a different interpretation of day-to-day realities in Argentina. This is an election about where the country is heading politically in the future.”

If Massa does well on Sunday, he may well be a candidate in presidential elections in two year’s time.

Fernández de Kirchner has already exhausted her two-term limit and is not eligible, although government insiders have suggested in the past that she wants to change the constitution in order to put herself forward. She would need a two-thirds majority in Congress in order to push such amendments through — and it appears unlikely the government coalition will get such numbers on Sunday.

“Before the primaries, the government was playing the card of changing the constitution,” said Labaqui, the university professor. “Either it was real or they were trying to delay a succession struggle, which would shift the focus away from the president as leader and turn her into a lame duck.”

What’s certain is that the government has no clear successor at the moment. The one-time darling of Peronism and current Vice President Amado Boudou has fallen out of favor after being embroiled in several corruption scandals. Although he is in charge while the president is on sick leave, the party has been at pains to keep the profile of the electric-guitar-playing, Harley Davidson-riding former economy minister as low as possible.

Walking near one of the capital’s main thoroughfares, Corrientes Avenue, 41-year-old Rodrigo Castari said he wouldn’t be voting for Victory Front candidates, who are also trailing opposition members in the city.

“They’re a disaster,” he told The Miami Herald. “Voting for them means more corruption and the same as before.” Castari, who lives outside the city limits in the province, said he would be voting for Massa.

“He’s the best — he’s the only one who can do anything,” he added.

The major winner in Sunday’s vote could well be the candidate from Buenos Aires Province. But whether this clears the way for a run by Massa in 2015 is another issue.

“The challenge Sergio Massa will have is sustaining momentum,” explained Labaqui. “Two years in Argentine politics is a very long time.”