Former Argentine President Cristina Fernandez de Kirchner waves during a rally in Buenos Aires, Argentina June 20, 2017. REUTERS/Marcos Brindicci

BUENOS AIRES (Reuters) - Candidates aligned with Argentina’s center-right government and those aligned with leftist ex-President Cristina Fernandez are in a technical tie in a key province ahead of October’s congressional elections, according to a poll published by newspaper Clarin on Sunday.

In Buenos Aires province, Argentina’s most populous, government-aligned candidates would take 28.5 percent of the vote, while Fernandez-aligned candidates would take 27.8 percent, according to the poll, which was carried out by the consultancy Management & Fit.

The figures put the two lists within the poll’s margin of error, Clarin said, though the newspaper did not specify the margin of error. The poll had 2,000 respondents.

Fernandez, who was president between 2007 and 2015, formed a new party independent of Peronism, Argentina’s dominant political movement, before announcing her bid for a Senate seat last month.

Although the October election is not expected to fundamentally change the balance of power in Congress, where no party has a majority, it has symbolic power for center-right President Mauricio Macri, particularly in Buenos Aires province, which is home to a quarter of the electorate.

Macri’s allies need a strong showing against Fernandez to convince investors he could win a second term and execute an ambitious agenda of economic reform.

Macri, scion of one of Argentina’s wealthiest families, eked out a surprise win in the province in 2015, launching him to the presidency and interrupting over a decade of populist, left-wing rule. But he has cut popular energy and transportation subsidies to get Argentina’s finances in order, earning some enemies in low-income towns.

In the poll, the 1Pais party of relatively moderate ex-presidential candidate Sergio Massa had 24.1 percent of voters in the province, putting it in third place.