Support for the conservative OVP has crashed from 34% to 26% in the wake of the affair, according to the survey published by newspaper Kurier on Sunday.
The outcome puts the party, which installed former foreign minister Alexander Schallenberg as the new chancellor, only marginally ahead of the opposition Social Democrats (SPO)’s approval rating of 24%, the paper said.
Kurz, 35, quit as chancellor under pressure from his junior coalition party, the Greens, after prosecutors placed him under investigation on suspicion of various degrees of bribery, corruption and breach of trust. He denies any wrongdoing.
Kurz remains leader of his party and is now also its top lawmaker in parliament, triggering opposition claims he is still exercising power behind the scenes.
Some 71% of the people questioned in the Kurier survey thought Kurz’s resignation as chancellor was justified, with only 22% saying it was unwarranted.
Anti-corruption prosecutors say they suspect conservative officials then in the Finance Ministry of using state funds to pay for manipulated polling and coverage favourable to Kurz to appear in a newspaper starting in 2016, when he was seeking to become party leader.
A poll by Unique Research for Profil magazine published on Saturday also showed how the Kurz affair has damaged the OVP.
The conservatives polled only 25% with Schallenberg as candidate, 10% down on earlier polls and the same level as the Social Democrats.
Two thirds of respondents told the Unique Research poll they thought there was substance to the allegations against Kurz, while 23% said they thought there was nothing to the affair.