Polls have opened in Sweden’s general election in what is expected to be one of the most unpredictable races in the country for decades, amid heated debate on immigration.

Sunday’s election is Sweden’s first since the government in 2015 allowed 163,000 migrants into the country of 10 million.

While far less than what Germany took in that year, it was the most per capita of any European nation.

It is highly unlikely that any single party will get a majority, or 175 seats.

Sweden election
Ulf Kristersson, leader of the Moderate Party, arrives to vote with his wife Birgitta Ed in Strangnas (Erik Simander/AP)

The latest opinion poll suggests that Prime Minister Stefan Lofven’s ruling Social Democrats will substantially lose seats but still emerge a winner with an estimated 24.9% of the votes.

The polls showed the far-right, anti-immigration Sweden Democrats would get 19.1% of the votes.

The centre-right Moderates party is set to take to take third place with 17.7%.

With a steady rise in popularity of the Sweden Democrats, immigration has become the hot topic of the election.

The party, rooted in a neo-Nazi movement, has worked to soften its image, and has played a role in breaking down longstanding taboos on what Swedes could say openly about immigration and integration without being shunned as racists.

During a heated debate of party leaders on Friday evening, the Sweden Democrats’ Jimmie Akesson caused a stir by blaming migrants for the difficulties they often have in finding employment.

Sweden Election
Sweden Democrats leader Jimmie Akesson at an election rally in central Stockholm (Maja Suslin/AP)

At the party’s rally on Saturday, he strongly criticised Mr Lofven’s government for “prioritising” the cause of asylum-seekers.

“This government we have had now . they have prioritised, during these four years, asylum-seekers,” Mr Akesson said, giving an exhaustive list of things he says the government has failed to do for Swedish society because of migrants.

“Sweden needs breathing space, we need tight responsible immigration policies.”

Mohamed Nuur, a Social Democrat candidate of Somali descent, said he sees Mr Akesson taking Sweden back to the past.

“For me, the Sweden that he (Jimmie Akesson) wants to see… that is not our future,” Mr Nuur said.

“That is to go back in history. For me, when he is saying that immigrants are not welcome to Sweden… he is trying to spread hate between the people. Actually, it’s the immigrants who built up this country.”