COPENHAGEN • Climate concerns topped the agenda for Danes as they voted yesterday in a general election in which the opposition Social Democrats are tipped to return to power after adopting the right wing's long-standing restrictive stance on immigration.

Opinion polls put the opposition centre-left Social Democrats, led by Ms Mette Frederiksen, at 27.2 per cent - a comfortable lead of almost 10 points ahead of Prime Minister Lars Lokke Rasmussen's ruling Liberal Party, which has been in power for 14 of the last 18 years.

"Many voters want change. In particular, the millennials, who can vote for the first time," Mr Flemming Juul Christiansen, a political scientist at Roskilde University, told Agence France-Presse (AFP).

About 50 people had lined up outside city hall in Copenhagen when polls opened yesterday morning.

Ms Amalie Falck-Schmidt, 29, said she wanted to vote early as it was important to "support democracy", and she was concerned about the environment. "I think it's climate that's the most important, so that's what I voted for," she told AFP.

Ms Falck-Schmidt is not alone. Some 57 per cent of Danes think the next government should prioritise climate change, according to a Gallup poll published in February. For those aged between 18 and 35, the figure was 69 per cent.

Pledges by Ms Frederiksen to boost welfare spending after years of cuts, and stick to a tougher stance on immigration, have gone down well with many Danes. Opinion polls indicated Ms Frederiksen, 41, will win the election.

The Socialist People's Party, heavily focused on environmental issues, is also expected to see a surge in its numbers, with opinion polls suggesting it could take 8.3 per cent of votes, almost double its 2015 score.

If the Social Democrats emerge victorious, they intend to form a minority government - common in Denmark's proportional representation system - relying on the support of the left or the right on a case-by-case basis to pass legislation.

As Denmark enjoys robust economic growth, almost full employment and strong public finances, the party has focused its campaign on climate issues and the defence of the welfare state.

Ms Frederiksen has taken a harder line on immigration to lure back some voters from nationalist parties like the Danish People's Party (DF). Her party backed tougher legislation on refugees and immigrants passed by Mr Rasmussen's centre-right minority government, which relied on DF support.

This included a ban on wearing the body-covering burqa and niqab face veil in public, as well as a so-called "jewellery Bill" that allows police to seize refugees' valuables to help pay their costs.

AGENCE FRANCE-PRESSE, REUTERS