STOCKHOLM (Reuters) - Final polls a day before Sweden's general election predicted a narrow victory for the center-left opposition followed by a complex task in building a stable government after Sunday's vote.
Saturday's polls gave the Social Democrats, Greens and Left parties a lead of 5.3 and 5.7 percentage points over the ruling center-right government, a much narrower gap than the opposition had enjoyed until recently and short of a majority in the 349-seat parliament.
"There is still a good distance between us," Social Democrat leader Stefan Lofven, a former welder who is in line to be Sweden's next prime minister, said in a television interview.
"I have always said it was going to be much closer than it looked like being a while back."
In spring, the three opposition parties - which do not comprise a formal coalition - had a lead of around 15 percentage points.
"We are going to fight right up to the last minute," Prime Minister Fredrik Reinfeldt, who heads the four-party Alliance government, said on TV.
A poll-of-polls by Novus for Swedish radio showed the gap between the center-left and center-right at 5.9 percentage points.
Widely admired for its strong economy, stable government and liberal attitude to immigration, Sweden nevertheless faces significant challenges which a weak government would struggle to tackle.
Unemployment is high, particularly among immigrants and young people, and a housing bubble threatens economic stability. The rise of the far-right indicates a society starting to question its role as what Prime Minister Reinfeldt has called "a humanitarian superpower."
Polls show voters are tired of a four-party Alliance coalition that has slashed taxes by more than 130 billion crowns ($18.25 billion) over the last 8 years, but is blamed for weakening the cradle-to-grave welfare state.
A split opposition has failed to capitalize on those concerns, despite promising more spending on healthcare and schools.
With the Social Democrats - the largest opposition party - looking like winning around 30 percent of the vote, prime minister-in-waiting Lofven could struggle to cobble together a stable administration.
"Just now, it looks more and more like there will be a change of government," said Magnus Hagevi, associate professor of political science at Linnaeus University.
"The current situation points to a very complex process to form a government," Hagevi said.
The Social Democrats have been coy about which parties they would reach out to if - as looks certain - they don't get a majority.
Lofven has said the Greens are a "natural partner", but together the two parties could be smaller than the current center-right government.
Bringing the Left Party into government or getting the backing of its leader Jonas Sjostedt, is an alternative.
But the former communists want to hike income and business taxes and exclude for-profit companies from welfare - policies that don't sit well with the Social Democrats or Greens.
Even with the Left Party, the three might end up short of a majority in parliament, leaving the anti-immigration Sweden Democrats holding the balance of power.
Saturday's polls showed the Sweden Democrats becoming the country's third-largest party after the Social Democrats and the Moderates of Prime Minister Fredrik Reinfeldt.
Both the center-right and center-left have said they will not cooperate with a party that wants a 90 percent cut in the number of asylum seekers Sweden takes in.
Lofven's task would become easier if Feminist Initiative, a left wing party, got into parliament. But polls show them just under the 4 percent threshold.
Support from Fi would also push the Social Democrats further to the left, making it harder to get support from parties currently in the Alliance, as Lofven has said he would like to do, in the event the Sweden Democrats hold the balance of power.
Saturday's poll by Novus, commissioned by TV4, showed the Social Democrats, Green and Left parties had 45.8 percent support against 40.5 percent for the four-party Alliance government - a 5.3-point lead.
In the previous Novus poll, published on Sept. 10, the opposition had a 3.6 percent lead.
A Sifo poll gave the three center-left opposition parties a lead of 5.7 percentage points over the Alliance, down from 6.2 percentage points on Sept. 10.
The Sifo poll showed the center-left with 45.7 percent support against 40.0 percent for the Alliance government.
US dollar = 7.1247 Swedish crown)
Additional reporting by Anna Ringstrom; Editing by Rosalind Russell