Former Chancellor Sebastian Kurz stunned Austria and left a power vacuum in his governing conservative party today by announcing he was leaving politics, after coming under criminal investigation for suspected corruption.

Mr Kurz, 35, who was one of Europe's youngest leaders, quit as chancellor in October at the behest of his coalition partner, the Greens, after prosecutors launched the graft inquiry, though he remained head of his People's Party (OVP) and a lawmaker.

Mr Kurz has been the dominant and most polarising figure of Austrian politics since 2017 when he became OVP leader and then chancellor, winning a parliamentary election and forming a coalition with the far-right Freedom Party (FPO).

"I am neither a saint nor a criminal," Mr Kurz said in an unusually long statement to the media today, giving thanks for a decade in government while denying any wrongdoing in the case in which he is one of 10 people suspected of varying degrees of breach of trust, corruption and bribery.

Mr Kurz said he had felt "hunted" because of hefty criticism during his time as chancellor. He has most recently come under fire for not doing more to prevent the latest wave of Covid-19 infections, which prompted the current national lockdown. He admitted to making mistakes but did not say what they were.

He led his party in two parliamentary elections in 2017 and 2019, becoming chancellor after both. But his time in government was mired in scandals including the graft investigation and his dismissal by parliament in 2019 after a video sting ensnared the then-leader of the FPO and their coalition collapsed.

Many conservatives believed Mr Kurz's successor as chancellor, career diplomat Alexander Schallenberg, was merely a place-holder until Mr Kurz could clear his name and return. Until October Mr Kurz was widely expected to remain chancellor for years.

His OVP is one of the main traditional parties in Austria but under Mr Kurz it has largely been built around him, leaving no obvious choice to succeed him as its strongman.

Mr Kurz said the OVP leadership would meet tomorrow but did not endorse anyone to succeed him. Various Austrian media said Interior Minister Karl Nehammer is the best-placed candidate.

A new OVP leader could also lead to a cabinet reshuffle, as party statutes say the leader can pick the party's ministers. The OVP is in coalition with the left-wing Greens and controls most ministries including foreign affairs and finance.