Independent candidate for the Senate Anthony Pesec has accused Australian Electoral Commission staff of giving voters the wrong information about how to vote for him, saying it affected the number of votes he received on Saturday.
Mr Pesec was running in the Senate as an independent with running mate Gary Kent, meaning the box above the line didn't include a name, but could still have been numbered.
Mr Pesec said some voters told him they were incorrectly told they couldn't number the box, some were told he had pulled out of the election, and some were told they didn't know how to vote for him.
His campaign team contacted the commission mid-morning on Saturday, after which a message was sent to polling booth staff, telling them to give the correct instructions if asked about the box.
"We got some feedback at some of the stations voters were being told to leave that box blank. That's when we realised we had a big problem," Mr Pesec said.
"There was confusion about even being allowed to put a number in that box."
A casual electoral commission staff member who worked on election day told The Canberra Times staff weren't told how to answer questions about the blank box, and that questions were asked by one in every four to five voters.
The staff member said they didn't remember a message coming through with new instructions on what to tell people about the blank box.
The staff member said they now believed they had given out incorrect information after copying the instructions other colleagues gave to voters.
Mr Pesec says scrutineers have noticed many ballot papers have numbered one to six above the line, all leaving his box blank. While the way independents for the Senate are treated is the same across the country, Mr Pesec believes because there were only seven columns in the ACT, people thought it meant one should be left blank.
While originally not intending to print how-to-vote cards in order to let people decide their own preferences, Mr Pesec said his campaign decided to print the cards after they realised there was confusion during pre-poll.
Mr Pesec said he needed to wait for the Senate ballot papers to be counted to see whether the instructions had a marked effect.
If particular polling places showed unusual levels of voting, or if there was a significant difference in above- or below-the-line voting for his ticket, that could show the impact.
Mr Pesec said he would be making a submission to the parliamentary committee on electoral matters that is set to undertake a regular review of the election.
"It's already tough enough as a non party member," he said.
Electoral Commission media spokesman Evan Ekin-Smyth said the commission was looking into the issue and would respond to Mr Pesec.
"All we can do is set out the ballot paper as electoral laws provide and provide instructions on that," he said.
"Ultimately if someone believes there is an issue that needs to change, it's not up to the AEC to change it, it would be a matter for Parliament."
Mr Ekin-Smyth said the electoral commission hadn't received complaints about instructions given from anyone other than Mr Pesec.