Results from Finland's parliamentary election illustrated the struggle by Europe's traditional political parties to retain supporters, with the centre-left Social Democratic Party winning the most votes and followed closely by a populist party that wants to temper national efforts to curb climate change.
Finns can expect a broad, ineffective coalition government for the next four years as the Social Democrats, who narrowly won weekend elections, focus on keeping the surging anti-immigration populists out, analysts said. "SDP is the prime minister party", Rinne said.
The Finns Party is part of an alliance that hopes to become the strongest faction in the European Union legislature and to radically transform EU policies on migration, families and the environment. The conservative National Coalition Party finished in third place with 17 percent of the vote and 38 seats.
In Sweden, Prime Minister Stefan Lofven has clung to power after his Social Democrats suffered their worst parliamentary election result in more than a century last autumn, enlisting the support of two liberal parties with a pledge to enact some right-wing policies.
The party is the only group in Finland - a country that has the highest air quality in the world, according to the World Health Organisation - to argue the next government should not speed up cutting carbon emissions to combat climate change.
Around lunchtime the leaders of the main parties were seen casting their ballots in their constituencies: Halla-aho in Helsinki, Rinne in the town of Mantsala in the south, and Petteri Orpo in the southwest city of Turku.
Earlier, he had urged people to "vote for some borders" during the general election campaign.
The Social Democrats came in as Finland's biggest party with 17.7 per cent of the votes, just ahead of the Finns Party on 17.5 per cent.
During the campaign, most parties expressed strong reservations about sharing a government platform with Halla-aho's party, while stopping short of ruling it out entirely.
"Rinne has been pretty clear that there are substantial ideological differences between the Social Democrats and the Finns Party". It's kind of a climate election. The populist Finns Party, however, is polling in second place with 16% support and has been gathering momentum among voters who find the climate change sacrifices proposed by other political parties too daunting.
Reform has been controversial in Finland and plans to cut costs and boost efficiency have stalled for years, leaving older voters anxious about the future.