Millions of Swedes voted Sunday in a close election that could see the Social Democratic government lose its 12-year grip on power to a center-right alliance vowing to trim and improve the famed Scandinavian welfare state. The four-party opposition bloc led by Fredrik Reinfeldt surged in last-minute opinion polls to overtake Prime Minister Goran Persson's Social Democrats and their two supporting parties. Still, analysts said the race was too close to call and both leaders predicted a photo finish. "We don't have a result yet," Reinfeldt told Associated Press Television News before joining the other alliance leaders for a stroll through downtown Stockholm. "We are confident that we have made a good election campaign." First results were expected within hours of polls closing at 1800 GMT. After 10 years in power, Persson, 57, is the European Union's second longest-serving prime minister after Luxembourg's Jean-Claude Juncker. But this year, he faces his strongest challenge yet from the center-right bloc, which is campaigning on a common platform for the first time. "My feeling is that this will be very even, very tough," Persson told TV 4's morning program. Persson says Sweden's social model - a market economy blended with a high-tax welfare state - is at stake. But the opposition led by Reinfeldt's Moderate Party insists it would not dismantle the system but help it survive by promoting jobs over welfare handouts. According to a survey released late Saturday by pollster Synovate Temo, the opposition had a clear lead with 50.8 percent, compared with 43.9 percent for the Social Democrats and their allies. About 1,700 people were interviewed in the Sept. 13-16 survey, which had a margin of error of plus or minus 3 percentage points. Sweden is enjoying strong economic growth - 5 percent in the second quarter compared with the EU average of 2.8 percent - but that does not appear to have given Persson's government the boost it expected. Reinfeldt, 41, accuses the government of failing to translate the growth into more jobs and claims the official statistics showing 5.7 percent unemployment are misleading. If you add people on sickness or disability leave or government job-training programs the figure is higher than 20 percent, he says. Another potential problem for the Social Democrats is that their partners in the 349-seat Riksdag, the small Left and Green parties, are demanding Cabinet seats as a condition for keeping Persson in power. Reinfeldt hopes wavering voters will ultimately opt for the alliance because it presents a clear alternative - a coalition government including Moderates, Christian Democrats, the Center Party and the Liberal Party - while the configuration of a new leftist government remains unclear. "I think we need new blood," said Kao Lindstrom, 40, after casting her ballot for the Moderates at a Stockholm polling station. "But many people I know are not sure." Persson is hoping for a high turnout among Sweden's 6.8 million voters, which historically favors the Social Democrats. "I've always voted for the Social Democrats and I guess I'll stick with them now," said Lars Hallen, a 59-year-old retiree. Britta Holmberg, 37, said she voted for the Green Party, because she feared the alliance was "a threat to the welfare system." Smaller parties such as the Feminist Initiative or the far-right Sweden Democrats will be hard pressed to reach the 4 percent threshold needed to enter parliament, polls show. The Sweden Democrats have largely been left out of political debates before the election because of their anti-immigration views. Twelve percent of Sweden's 9.1 million residents are foreign-born, with many recent arrivals from the Balkans, Iraq and former Soviet republics. Also Sunday, Stockholm residents were voting in a referendum on whether to introduce congestion fees for drivers entering or leaving the city. The traffic toll, tested in a trial period January-July, is meant to bring in money for improving public transportation and better roads, while reducing pollution and congestion in the capital.