Ivas's act was inappropriate and he was issued a reprimand, the party said in a statement.
The deputy's irresponsible conduct did not affect the outcome of the vote because the parliament speaker repeated the vote after Independent Democratic Serb Party (SDSS) deputy Milorad Pupovac lodged a complaint, the party said.
Ivas admitted on Friday to having pushed once the voting button of HSLS deputy Ivan Cehok, who at the time was not in the parliament hall.