Prime Minister Fredrik Reinfeldt's governing Alliance appears to be increasing its support in the final stages of its election campaign, with the Social Democrat-led opposition slipping in the polls after dominating for months.
The Social Democrats, Green and Left parties have made no formal agreements on whether they would form a coalition government, but grouped together Red-Greens currently have a narrow lead of around 5 percent, according to several surveys released this week.
An even tighter lead of 3.6 percent was suggested in a poll by Novus for Swedish channel TV4 on Wednesday.
According to the Novus poll, the election race is now so close that without the support of the Left Party, the Social Democrats and the Greens actually lag behind the Alliance by 2.9 percent.
Pollsters say it is the smaller Alliance parties that are making the biggest gains, rather than Prime Minister Fredrik Reinfeldt's Moderates.
But so far it is unclear whether the Liberal Party, Centre Party or the Christian Democrats will be the most successful at increasing their votes.
One theory is that middle-class voters are seeking a limited change in Sweden and are therefore deciding not to abandon the Alliance, but to vote for one of the smaller parties rather than the Moderates.
There is also speculation that turnout could be lower than in previous years.
There are four parties in the current governing Alliance. Photo: TT
Meanwhile Prime Minister and Moderate Party leader Fredrik Reinfeldt said on Wednesday that he was open to working with other opposition parties currently outside the Alliance, including the anti-immigration Sweden Democrats.
The nationalist party, led by Jimmie Åkesson is currently polling just above 10 percent; almost double their vote in 2010, which would make them Sweden's third or fourth largest party in Parliament.
On Wednesday Reinfeldt told the Reuters news agency that he would continue to exclude the Sweden Democrats in deals on issues like asylum and immigration, but that he would seek "cooperation in other policy areas."
The Sweden Democrats have previously tended to back the governing Alliance on most key issues including tax cuts and boosting Sweden's defence budget.
However, on migration policy Reinfeldt has sought to isolate the Sweden Democrats by agreeing a wide-ranging deal with the pro-immigration Greens.
"The goal is to isolate the Sweden Democrats from influence, to not in any context become dependent on them or assume their support," said Reinfeldt.
Jimmie Åkesson's Sweden Democrats are set to increase their support. Photo: TT
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"I wouldn't put a bet on the final outcome," Li Bennich Björkman, a Professor of Political Science at Uppsala University in eastern Sweden, advised The Local.
"It is usually the case that the race gets tighter in the final week, but this time we really have a scenario where we can't say who will be in government next week," she said.
She believes it is "entirely possible" that a coalition could be formed that is neither made up of the current combination of Alliance parties or a Social Democrat-led group of Red-Greens.
"The Social Democrats don't actually have a formal agreement to team up with the Greens and in fact all of the major parties have kept it a bit open in terms of who they might co-operate with in future," she adds.
"I think it is quite likely that we might see something different happening in this election."
Green Party spokesperson Gustav Fridolin told newspaper Dagens Nyheter that he was prepared for a tough finale to the election campaign.
"The election will be decided in these last days," he said.
"Do voters want to have four more years of a government that has ruled for eight years and prioritized tax cuts, or do they want something new?".