The far-right Sweden Democrats (SD), an anti-immigration party with roots in the neo-Nazi movement, are tipped to win around 20 percent of votes, according to an average of seven polling institutes published in the past 10 days, up from 13 percent in 2014 elections.
That could make SD Sweden's second biggest party behind Prime Minister Stefan Löfven's Social Democrats.
SD has capitalized on voters who feel left behind by traditional parties in favour of the 400,000 asylum seekers who have arrived since 2012, whom they believe are straining the country's famed welfare model.
Immigration, integration, healthcare, the climate and education have been Swedes' main concerns in the election campaign.
In an op-ed published in Sweden's paper of reference Dagens Nyheter just days before the election, Löfven urged Swedes to vote for a "stable government … capable of leading Sweden in uncertain times".
"Healthcare queues are too long in some areas, unemployment among foreign-born people is still too high, and crime and insecurity need to be curbed," he said.
Prime Minister Stefan Löfven next to his campaign bus. Photo: Stina Stjernkvist/TT
The seven opinion polls put support for the left-wing bloc at around 40 percent, and 37 percent for the opposition centre-right Alliance (conservative Moderates, Liberals, Centre and Christian Democrats).
Neither bloc would hold a majority in parliament, and would have to seek support elsewhere to pass legislation.
Tough talks ahead
SD has said it is willing to collaborate with either the left or the right, as long as it can shape the country's immigration policy.
But so far, no parties are willing to negotiate with SD.
"It's difficult to single out the most likely (government) scenario" after this election, University of Gothenburg political scientist Ulf Bjereld told AFP.
Thorny, drawn-out negotiations are expected after the election.
Political observers suggest the most likely outcome would be a new Löfven government, with an even weaker minority than it has now.
The outgoing "red-green" bloc is made up of the governing Social Democrats and the Greens, who get informal support in parliament from the ex-communist Left Party.
Voter turnout is traditionally high in Sweden, hitting 85.8 percent in 2014.
But more than a quarter of the country's 7.5 million eligible voters remain undecided, according to a Sifo poll published on Wednesday.
In the final days of the campaign, Löfven opened up for a cross-bloc collaboration with the Centre and Liberals.
SD's rising influence
Meanwhile, the main challenger for Löfven's job, Moderates leader Ulf Kristersson, is intent on ousting the Social Democrats, which have dominated Swedish politics since the 1930s.
The leader of the four-party Alliance, Kristersson, like Löfven, is competing with the far-right for voters.
Ulf Kristersson, the leader of the Moderates, shakes hands with a voter. Photo: Fredrik Sandberg/TT
The Alliance would however need the support of the far-right to pass legislation, and SD would make demands in exchange for its backing.
It would either ask for policy concessions – which the four parties have so far ruled out – or key positions on parliamentary commissions that draft legislation.
SD wants to put an end to Sweden's current asylum system, vowing instead to "help refugees return to their home countries".
Kristersson has repeatedly refused to negotiate with SD.
An Ipsos poll on August 28th suggested however that a third of Moderate voters want him to include SD in a future right-wing government.
Sweden Democrat leader Jimmie Åkesson speaking in Landskrona. Photo: Johan Nilsson/TT
Jimmie Åkesson, the 39-year-old SD leader, has warned the Social Democrats and the Moderates they can't go on seeing SD "as a passing illness that has temporarily afflicted parliament".
The seven polls put his party's average support at about 20 percent, but individually, the polls show support ranging from 16 to 25 percent.
Opinion polls may be underestimating support for the far-right, some political analysts have suggested.
If SD were to become the biggest party it would be unable to build a government or majority in parliament, but it would wield considerable influence.
Created in 1988, SD has attracted voters disillusioned with the Social Demcorats and those in rural areas where industries and public services have been cut back.
The party's nationalist rhetoric, with calls for a "Swexit" and demands for immigrants to assimilate, appeals to a growing number of voters.
Article by AFP's Pia Ohlin