Voting is under way in elections in Austria that could result in the former chancellor Sebastian Kurz renewing a controversial pact with the far right to reclaim his position as the world’s youngest state leader.

The conservative-nationalist coalition government collapsed in May after the emergence of a covertly filmed video in which the then deputy chancellor and Freedom party (FPÖ) leader, Heinz-Christian Strache, offered lucrative public contracts in exchange for campaign support to a woman purporting to be the niece of a Russian oligarch.

But with Strache banished from office, the FPÖ headed by two new leaders and the 33-year-old Kurz emerging from the scandal largely unscathed, a renewed alliance between the two parties remains on the cards.

Now led by the hardline former interior minister Herbert Kickl and the former presidential candidate Norbert Hofer, the FPÖ has openly rallied for a reunion with Kurz’s Austrian People’s party (ÖVP). Its campaign video shows Hofer readjusting a portrait of the youthful former chancellor to stop it “tilting to the left”.

The latest polls predict Kurz’s ÖVP emerging as the strongest force with about 33% of the vote, followed by the centre-left Social Democratic party (SPÖ) on 22% and the FPÖ on 20%.

The Austrian Green party, which in 2017 failed to get over the 4% threshold for the first time since 1983, has polled at about 13%, fuelling speculation Kurz could opt for a three-way alliance with it and the pro-business, liberal NEOS party.

A “grand coalition” with the centre-left SPÖ, which has been the norm for much of the period since the second world war, has come to be associated with political stasis and infighting and would sit uneasily with Kurz’s reformist agenda.

About 6.4 million Austrians are eligible to vote until 5pm local time (1600 BST), when voting booths close and the first exit polls will be published. The first official results will be published at about 9pm local time.