The far-right Sweden Democrats (SD) who originated from the neo-Nazi movement, have sought to clean up their image in recent years with a sweeping revamp that has widened their appeal.
Narrowly trailing in the opinion polls behind the Social Democrats, which heads the current coalition government, and neck-and-neck with the conservative Moderates, SD leaders are hoping to cause an upset in Sunday's legislative elections.
"We know that we are underestimated (in the polls) as we have been historically, I therefore don't exclude the possibility of us becoming the largest party," SD leader Jimmie Akesson told AFP on the sidelines of a rally in the southern city of Ystad in late August.
The party currently has 42 of the 349 seats in parliament after six members left, including the leader's mother-in-law, while another lawmaker was excluded over anti-Semitic remarks at the end of 2016.
The Sweden Democrats were formed in 1988 in the southern city of Malmo during a meeting attended by former Nazi group members and an ex-volunteer in the SS, among others.
The turning point came in the 2000s, when SD leaders decided to turn the party "into an ordinary one", a goal that upset core members by shifting its race ideology to anti-multiculturalism, according to Anders Sannerstedt, a political scientist.
"The initial links with white and Nazi supremacist organisations have been effectively abandoned," he said.
- 'Try to normalise' -
In October 2012, Akesson was forced to announce "zero tolerance against racism and extremism" and several members were kicked out.
But his orders have been regularly defied by some local party representatives and grassroot activists.
Senior SD member Bjorn Soder, the second deputy speaker in parliament, said last year that Jews should not be considered Swedish unless they assimilate.
"For their leadership, the crucial issue has been to try to normalise the party, although a lot of statements indicate there's still a long way to go," said Jens Rydgren, a sociologist specialising in radical groups in Europe.
The anti-racist magazine Expo and the daily Expressen recently revealed that several SD local election candidates -- whose votes will be held one the same day as the legislative polls - were former members of the National Socialist Front (NSF) and other small neo-Nazi groups.
Some continue to pay their party contributions.
According the Sweden's statistics authority, a quarter of SD's supporters are men aged 18 to 24.
Emil Pettersson. 18, is among them and admits that he was attracted by the party's tough immigration policies.
"They haven't really said anything racist," he insisted ahead of Akesson's appearance at the Ystad rally.
The SD were able to capitalise on the migration crisis of 2014 and 2015.
Sweden at the time welcomed nearly 250,000 asylum seekers, a bigger proportion of its (10 million) population than any other European country.
The Sweden Democrats' rise, however, began before the migration wave, making gains in the polls from 2010 to 2014.
- Growing influence -
Their influence in public debates also continues to grow.
In 1998, only three percent of Swedish voters cited migration as a reason for choosing who to elect. Twenty years later, it's one of their main concerns along with healthcare and education.
In early 2016, the Scandinavian country reinstated border controls and introduced several measures intended to dissuade asylum seekers.
Both turned into a symbolic victory for the far-right.
"The SD have been able to say 'we warned against this situation for many years, now the other parties start to imitate our policy,'" Anders Sannerstedt said.
On this particular issue, the SD's views do not differ much from the centre-right Alliance including the conservative Moderates, the Centre party, the Liberals and the Christian Democrats, Sannerstedt added.
At the local level, some members of the Alliance have already begun to crack under pressure from voters.
In Akesson's southern hometown of Solvesborg, the Christian Democrats and the Sweden Democrats announced the opening of negotiations before the municipal elections.
The Moderates, with 40 percent of their supporters spread across the nation, say they are open to discussion with the Sweden Democrats, to beat the local left.