In addition to immigration, violent crime is also a key issue. It follows a string of shootings and grenade attacks in recent months. On August 13, masked men set alight up to 80 cars in Gothenburg and other towns on Sweden's west coast, in what the police said appeared to be a series of coordinated attacks.
In response to the arson attacks, Prime Minister Stefan Lovren told Swedish radio: "I am really furious, what the hell are they up to?"
"Society will always act hard against this and we must continue to do so… We will do what needs to be done to take care of it and go in hard against this crime," he added.
Another electoral issue, which has had minimal support among voters, is a so-called "Swexit" vote. Sweden's Democrats have said they would seek to hold a referendum over whether the country should join Britain and leave the EU.
Carl Bildt, the country's former prime minister, described the prospect of a "Swexit" referendum as "the biggest single danger to Sweden's future prosperity."
Sweden's robust economic performance over the past few years has barely featured in this political campaign.