The Social Democrats led by Mette Frederiksen were the biggest party with around 26 percent of votes, based on 94.1 per cent of the votes counted.- AFP Photo

COPENHAGEN — Denmark's opposition Social Democrats won on Wednesday's general election after a campaign focused on concerns over the climate, welfare and immigration, as support plunged for the far right and surged for the main green party.

Liberal Prime Minister Lars Lokke Rasmussen, whose party has been in power for 14 of the past 18 years, conceded defeat after the Social Democrats emerged as the biggest party with 25.9 per cent of votes, giving the left-wing bloc a majority of 91 of the 179 seats in parliament, with 100 per cent of votes counted.

Rasmussen's Liberal Party won 23.4 per cent of the votes, up almost four points since the 2015 election, but the rightwing bloc only took 75 seats.

"We had a really good election, but there will be a change of government," Rasmussen told supporters late Wednesday.

The leader of the Social Democrats and the likely next prime minister, 41-year-old Mette Frederiksen, said Danes had "chosen a new majority, and a new direction".

Rasmussen's government was brought down by a collapse for the anti-immigrant Danish People's Party, which has informally supported his minority coalition to pass legislation.

The Danish People's Party, which has supported successive minority rightwing governments in exchange for tighter immigration policies for the last two decades, saw its support more than halved to 8.7 per cent, the party's worst score since 1998.

Party head Kristian Thulesen Dahl told supporters at an election night rally that the party hadn't been "good enough" and he shouldered the blame, but also said he wanted to continue as leader.

"I'm not abandoning ship in the middle of the storm, I take the responsibility to once again move the party forward," he said.

As restrictive immigration policies have been broadly adopted by almost all other parties, the Danish People's Party has lost its unique appeal with voters.

U-turn on immigration

The Social Democrats, last in power between 2011 and 2015, were widely seen as favourites going into the vote. 

Led by Frederiksen -- a party veteran who made her debut in parliament at 24 -- the Social Democrats have also changed their tone on immigration.

In the early 2000s, she denounced Denmark's policy as one of the "toughest in Europe".

But under her leadership, the Social Democrats last year proposed, as part of their crackdown on immigration, to send asylum seekers to special camps in North Africa while their requests are processed.

With most parties in agreement on a tough immigration policy, and as Denmark enjoys robust growth, almost full employment and strong public finances, the Social Democrats focused their election campaign on climate issues and the defence of the welfare state, promising to reverse budget cuts to education and healthcare. — AFP