Liberal MP Bridget Archer has defended the Australian Electoral Commission, warning that it was "irresponsible to cast doubt on the integrity" of the body.
The MP's statement is in stark contrast to many of her Coalition colleagues, who, along with some no campaigners, aired concerns over whether crosses count as valid votes in the voice referendum.
Archer told Guardian Australia "my advice to voters would be simply to write 'yes' or 'no' on the ballot as instructed."
Her statement comes after another Liberal, shadow minister for finance and special minister of state, Jane Hume, told Sky News on Sunday it was "really a commonsense issue" and that it was an "inconsistency" for a tick to count as a yes but cross not counting as a no.
"I think it's important to point it out – it does seem to be an inconsistency. I know it's occurred in the past. But ... I think we want to make sure that integrity is central to the voice referendum," she said.
Hume argued that counting votes was another integrity measure and it was important to "give people comfort that the result is as clean and neat as possible".
But Archer, who is an open supporter of the voice and has often drawn the ire of her colleagues with her contrarian position towards policy matters, defended the AEC.
"The AEC has been very clear in relation to this matter, they are a robust and trusted institution," she said.
"It is irresponsible to cast doubt on the integrity of the AEC and their established processes in a deliberate attempt to confuse people or induce them to question the validity of the result."
Fair Australia, an unofficial face of the no campaign for conservative group Advance Australia, has sought to weaponise the issue.
A video featuring the comments of AEC Commissioner Tom Rogers defending the process set to a cover of Leonard Cohen's Everybody Knows has appeared on their Twitter feed, featuring the lyrics "everybody knows that the dice are loaded" and "everybody knows the fight was fixed".
The special minister of state, Don Farrell, said "campaigners against Indigenous recognition are truly grasping at straws".
He said the guidelines on how to complete a ballot paper had been the same for decades, and "at no point" during their nine years in government "did they (the coalition) ever raise this issue, nor did they raise it when they voted in favour of the referendum machinery legislation earlier this year".
The Labor chair of the committee inquiry that examined the referendum machinery bill, Kate Thwaites, said the process - including ticks and crosses - under the savings provisions "wasn't raised by witnesses in public hearings nor by members of the committee, including the Coalition members".
"That is the correct place to raise issues if you have problems with those processes – not to call into question the integrity of election bodies or other matters," she said.
Dean Parkin, the director of Yes23, told Sky News this wasn't the AEC's first referendum, stating "I think we should trust that the AEC knows exactly what he's doing."
"I think it has been a bit of a kerfuffle but ultimately the AEC know what they're doing … and Australians can have great confidence in our system."
On Friday, the Minister for Indigenous Australians, Linda Burney, defended the AEC, labeling them a "trusted entity."
"The idea that we are doing something different, or the AEC is doing something different this referendum, is simply wrong," she said.
