By Anna Ringstrom and Simon Johnson
STOCKHOLM, Sept 13 (Reuters) - Sweden's centre-left parties, which back Social Democrat leader Magdalena Andersson for prime minister, held an early lead with 51.3% of the vote in a parliamentary election on Sunday, an exit poll by broadcaster SVT showed.
Early results from the Swedish Election Authority are expected within hours after polls closed at 8 p.m. (1800 GMT). A separate election-day poll conducted by broadcaster TV4 also showed the centre-left in the lead.
If the centre-left's lead is confirmed by official results, it would halt Sweden's recent rightward drift away from its liberal traditions in an election that many analysts viewed as a referendum on the Sweden Democrats, a grouping with roots in the neo-Nazi fringe.
Swedish exit polls, while often indicative of the final outcome, have not always proved accurate. In 2022, an exit poll projected Andersson's bloc would prevail, but the election was ultimately won by a right-wing coalition headed by Ulf Kristersson, who is now Sweden's prime minister.
As exit poll readings were broadcast, cheering broke out at the election gatherings of the centre-left parties while the outcome was met with silence among the far-right Sweden Democrats, with the exit polls indicating a setback after they boosted their vote share over several consecutive elections.
"If this holds up, Magdalena Andersson will become our country's prime minister," the Social Democrats' party secretary Tobias Baudin told SVT after the exit poll results were announced.
The SVT exit poll gave the centre-left bloc 183 seats, above the 175 needed for a majority, while the right-wing parties were set to win 166 seats.
"There is a wish for a kind of change," Marie Demker, professor of political science at Gothenburg University, said.
"How that change is going to work out with these different red lines that these parties have drawn is tomorrow's worry."
Many Swedes have expressed wariness over Kristersson's push towards strict migration limits and saw his pre-election promise to bring the Sweden Democrats into government as a step too far.
"This is not what we hoped for, but it's not the final results so we'll have to see," the Sweden Democrats deputy party leader Henrik Vinge told TV4.
"You typically see some decline when you're part of the ruling coalition," he said.
Kristersson, who has trailed in opinion polls throughout his four years in office, had been catching up in the final weeks of campaigning, with Andersson and her Social Democrats losing ground.
Critics say Kristersson's government is undermining civil liberties while forcing immigrants to conform more closely to Swedish cultural norms or leave the country, urged on by both inducements and penalties.
Electoral success for the Sweden Democrats would be welcomed by Europe's ascendant far-right parties, which were bolstered by the anti-immigrant Alternative for Germany's win in a German state election last week.
The far right hopes for gains in upcoming elections across Europe, with the National Rally's bid for the French presidency next year potentially its biggest prize.
(Reporting by Niklas Pollard, Simon Johnson, Johan Ahlander and Tom Little; additional reporting by Ilze Filks, Ardee Napolitano, Janis Laizans for Reuters TV, Greta Rosen Fondahn, Marie Mannes, Terje Solsvik and Anna Ringstrom; Writing by Niklas Pollard and Justyna Pawlak; Editing by Peter Graff, Philippa Fletcher and Edmund Klamann)
