Norway's Labour party under Jonas Gahr Støre has won a second term in general elections, ahead of a populist right-wing party that doubled its vote.

In a country used to minority governments, Labour has a chance of forming a narrow two-seat majority in the 169-seat Storting, if it secures the support of four smaller parties on the centre left.

Norway's four million voters came out in big numbers, and the turnout of 78.9% was the biggest for years.

The anti-immigration Progress Party of Sylvi Listhaug made the biggest gains, securing almost 24% of the vote and 48 seats.

Jonas Gahr Støre, 65, told jubilant supporters that even though right-wing forces were on the rise in Europe, social democrat parties could still win elections.

With most votes counted, Labour won 28.2% of the vote and 53 seats, an improvement on its showing in the 2021 election.

The campaign was initially dominated by foreign policy, including the wars in Gaza and Ukraine, but the run-up to the vote focused on rising living costs, the oil industry and reforming a wealth tax that has seen hundreds of Norwegians leave the country for Switzerland.

Despite its small population of 5.6 million, Norway punches above its weight on the international stage. A founder member of Nato, it shares an Arctic border with Russia and is part of the EU's single market but not a member state.

Support for Labour was buoyed earlier this year when former Nato chief Jens Stoltenberg, a popular figurein Norway, joined the government as finance minister.

Sylvi Listhaug, 47, congratulated the Labour leader on his party's victory but told supporters that Norway had "four tough years ahead" under the left.

Her Progress Party has no hope of forming a coalition as parties on the right fell three seats short of the 85 needed for a majority.

The Conservatives lost ground with 14.6% and their leader, former prime minister Erna Solberg, has said she is unlikely to stand again.

Coalition building is likely to take several weeks, and if Labour succeeds in forming a majority it will have to overcome policy disagreements with smaller parties on the future of the oil industry and investments by Norway's enormous sovereign wealth fund.