Sweden's centre-left opposition has edged ahead of the ruling right-wing government in a knife-edge general election, with days of uncertainty expected before a final result is confirmed.The left-leaning bloc, led by Social Democrats leader Magdalena Andersson, was projected to win 176 seats in the 349-seat Riksdag, based on votes counted from 6,195 of Sweden's 6,312 electoral districts, the country's election authority said. The right-wing governing bloc of prime minister Ulf Kristersson trailed with 173 seats, separated by roughly 20,000 votes, with around 94 per cent of the vote counted on Monday morning. Exit polls from public broadcaster SVT had initially shown the left-wing parties ahead by several percentage points, prompting jubilation at the Social Democrats' election night gathering in Stockholm, though the mood shifted to quiet waiting as the closer preliminary results came in.Sweden elects its parliament through a proportional representation system, with parties needing at least 4 per cent of the vote to win seats. More than 8 million of the country's roughly 10.6 million people were eligible to vote. The country's political landscape is split between two four-party blocs, on the left and the right, meaning the outcome hinges less on any single party's result and more on which side can assemble a majority. Final results are not expected before Wednesday, when local election boards count postal votes that arrived too late for polling day, along with ballots cast from abroad.Green Party members react to the presentation of the exit poll at the election night watch party, in Stockholm (AP)Speaking early on Monday, Mr Kristersson said the outcome remained genuinely uncertain, though he pointed to what he described as a broader ideological majority in parliament. "There is a very clear non-socialist majority, or non-left leaning economic majority in the Swedish parliament," he said. "When we have the final result it's a good idea to look at possible combinations. I will actually take note of that and at least figure out whether there are any possibilities." No major media outlet had called the result. Ms Andersson urged her own supporters to wait for the final count. "We must wait for the final election result," she said. "Right now we are leading, but we have to wait for the final result."Moderates party leader Ulf Kristersson speaks during an interview during the Moderates' election night watch party in central Stockholm (Reuters)Mr Kristersson has governed Sweden since 2022 at the head of a three-party centre-right coalition, relying on outside support from the Sweden Democrats, a party with far-right roots that has moved toward the political mainstream, to secure a parliamentary majority. The Sweden Democrats had been promised cabinet posts this time had the governing coalition been returned to office. In a break from a longstanding taboo, Mr Kristersson pledged before the vote to bring the party directly into government as he seeks to build a majority right-wing coalition. Since taking office, his government has abolished permanent residency for refugees, tightened welfare rules and stepped up expulsions of people without the right to remain in the country.Swedish Social Democratic Party Magdalena Andersson claps on stage as the general election's voting results are released in Stockholm, Sweden (Reuters)Ms Andersson, who served as prime minister from 2021 until losing power at the last election, would need to secure a coalition agreement with other parties to return to office, and her own bloc faces internal tensions of its own, with disagreements over migration policy, a proposed tax on billionaires and the construction of new nuclear reactors. Her Left Party and Centre Party partners, in particular, differ sharply on economic policy, which could complicate efforts to pass a budget even if her bloc secures a majority.