Social Democrat Chancellor Werner Faymann's government coalition may well survive, but opinion poll trends suggest the FPO could overtake his conservative junior partner, the People's Party. Austria's overall prosperity at a time of hardship in Europe has done little to dampen historic unease at immigration.
"Love thy neighbor. For me, this means our Austrians," urges FPO leader Heinz-Christian Strache in campaign posters. The party promises to raise pensions and set a minimum wage and warns of asylum-seekers "leading Austrians around by the nose".
Some voters unhappy with establishment parties are attracted to the fourth-placed Greens or a new rival eurosceptic party formed by the Austro-Canadian founder of Magna International, Frank Stronach, which eschews the FPO's anti-foreigner and anti-Islam stance.
But the FPO remains the most popular anti-establishment party, scoring 21% in an opinion poll published on Monday, two points behind the People's Party (OVP) and up from 18% in 2008.
"I am the only one who wants to break up and change this red-black system," Strache told Reuters in an interview last week, referring to the ruling coalition.
Austria received 17,400 asylum claims in 2012, a 21% increase over the previous year compared with an 8 percent average increase for industrialised countries. The highest numbers came from Afghanistan and Russia - mostly Chechnya.
The Alpine nation's geographic position at the eastern edge of western Europe made it for decades an important destination for refugees and immigrants from the east.
Unlike in neighbouring Germany, where Chancellor Angela Merkel won a landslide victory on Sunday partly on the strength of the German economy, many Austrians feel hard done-by despite the lowest EU jobless rate and economic growth clearly above the EU average.
"You might ask: Why in Austria, which is such an obscenely prosperous place?" said Oxford historian and All Souls emeritus fellow Peter Pulzer, author of books on the Austrian and German right wing. "Part of the FPO's appeal is to those who are benefiting from the welfare state but don't want others to."
The FPO rejects the notion it is anti-foreigner, preferring to describe itself as "pro-Austrian"; but it continues to attract a neo-nazi fringe which has no other party to join and warns continually of an "Islamicisation" of Catholic Austria.
There is, however, no evidence of any association with anti- foreigner violence, which remains rare in Austria.
A cult of personality surrounds Strache, or "HC". Last week he released a rap song entitled "Stand up if you're for HC" sung by the leader dressed in leather jacket and sunglasses while party workers awkwardly dance and clap. (www.hcstrache.at)
A comic book of cautionary tales the FPO sent voters this week, featuring "HC Man" as a kind of superhero, urged: "Daham statt Islam" - "Homeland, not Islam" - and Strache has called burqa-clad Muslim women "female ninjas".
Around 1.6 million people, or 19% of the Austrian population, are first- or second-generation immigrants. Around a third are from other EU countries, another third from the neighbouring former Yugoslavia, and most of the rest are Turks.
Anti-Turkish feeling in Austria, whose capital was twice besieged by the Ottoman Empire in the 16th and 17th centuries, is such that Chancellor Faymann felt forced to deny having produced a Turkish-language election poster during a TV debate with Strache last week.
Opinion polls suggest the ruling parties will win just enough votes for another term, an option preferred by Chancellor Faymann but not necessarily by the OVP, which flirts with a center-right alliance.
The best chance of such a right-wing alliance's taking power is that the OVP performs so poorly that pro-Europe leader Michael Spindelegger has to resign.
Political analyst Wolfgang Bachmayer, head of the OGM marketing institute, said: "One doesn't know how the leadership positions will look after the election... then the OVP's attitude towards the Blues (FPO) could perhaps be different."
The biggest threat to the FPO comes from the new party of 81-year-old industrialist Stronach, known as Team Stronach.
The party has garnered up to 10% in opinion polls, largely at the FPO's expense, triggering a peculiarly Austrian macho rivalry that culminated in the octogenarian and the 44-year-old Strache publishing topless pictures of themselves.
Despite his public derision of Stronach, Strache does not rule out a coalition with his party. And even if Strache remains outside government, the main parties are likely to come closer to his position as the euro crisis continues, Bachmayer said.
"I know...that there is a considerable percentage of voters for the SPO and the OVP - both clear pro-Europe parties - that does not agree with the EU course," he said.