"Obviously, I'm tired of hearing every day that I'm not fit for the job," Hofer told an Austrian tabloid newspaper
The head of Austria's far-right Freedom Party (FPO) resigned on Tuesday in a surprise announcement following a months-long power struggle with the radical wing of the party.
"My journey as head of the FPÖ comes to an end today. I wish my successor in this position every success in the future," Norbert Hofer wrote in a statement.
Hofer, 50, lost the 2016 election for the largely ceremonial post of Austrian president against Alexander Van der Bellen. He was then named transport minister and became the FPÖ party leader in September 2019 after his predecessor, Heinz-Christian Strache, was forced to step down over a corruption scandal.
'Ibizagate' led to the collapse of the ruling coalition between FPÖ and Chancellor Sebastian Kurz's People's Party.
Hofer said in his statement -- released after a near month-long stay at a physiotherapy clinic to receive treatment to deal with the aftereffects of a 2003 paragliding accident -- that "it was was difficult to rebuild the party after the sudden end" of the coalition.
In recent months, his legitimacy at the helm had been challenged by party chairman and former Interior Minister Herbert Kickl.
Kickl leads the more radical wing of the party, created in the 1950s by former Nazis, and has already stated his intention to lead the party through to the 2024 parliamentary election.
Asked by Austrian tabloid Österreich whether his withdrawal was linked to his conflict with Kickl, Hofer replied: "Obviously, I'm tired of hearing every day that I'm not fit for the job."
He said he wanted to remain as vice-president of parliament and did not yet know whether he would run in next year's presidential election.
FPÖ party chairman Harald Stefan said in a statement that Hofer's resignation "came as a complete surprise".
"I will therefore immediately contact the other member of the Federal Party Presidium so that the responsible bodies can meet immediately," he added.