The far-right Sweden Democrats appear to be close to causing a huge upset in the country’s neck-and-neck election cliffhanger.

The populist anti-immigration party, which emerged from the neo-Nazi movement in the late 1980s, has increased its polling at each of the past nine elections, and on Sunday looked to have gained 21% of this year’s vote, according to near-final results.

If it transpires that has happened after the full count, they will become the country’s second-biggest party.

Then, a bloc of right-wing parties, including the Sweden Democrats, is expected to defeat a left-wing bloc headed by Prime Minister Magdalena Andersson and form government.

However, the result was so close the election authority said it would not be known before Wednesday when some uncounted votes, including those cast abroad, have been tallied.

Exit polls at first predicted victory for the incumbent left-wing coalition, but results later suggested the right-wing bloc could narrowly win.

Currently, with 94% of votes counted, the right-wing bloc appears to hold a lead of under one percentage point over the ruling centre-left group led by Prime Minister Ms Andersson.

Sweden Democrats leader Jimmie Akesson told his supporters at an event in Stockholm he was “proud” to be on track to become the country’s second-biggest party.

Shunned

While his party has its roots in the white nationalist movement, years ago it began expelling extremists.

But despite its rebranding, voters long viewed it as unacceptable and other parties shunned it.

That has changed in recent times, and pundits say its result in this election shows just how far it has come in gaining acceptance. During the campaign, its tough policies on law and order and immigration started to draw support from the centre-right.

Mr Akesson is unlikely to become prime minister even if the right-wing bloc wins the largest number of seats. The four parties in the group will select the cabinet positions and Moderate Party leader Ulf Kristersson is the current favourite to take the role, but will have a tricky line to walk between all parties – particularly one that has polled more votes than his.