It's unclear why new laws to enforce voter identification at polling booths are needed, federal parliament's bipartisan human rights committee says.
Proposed laws would make it mandatory for voters to show ID when casting a ballot.
The laws have raised concerns they may disproportionately affect disadvantaged people who are homeless or live in remote Indigenous communities.
The committee, chaired by Nationals MP Anne Webster, said the bill risked contravening human rights laws by denying people the right to take part in public life and not be discriminated against.
The government is arguing safeguards in the bill, such as accepting a wide range of identification, having another voter vouch for your identity and having the ability to cast a declaration vote, aim to ensure no person is left unable to cast their ballot.
But the committee said it remained concerned about the perception the law would have on voters and how it would operate in practice.
"Noting that the next federal election is required to be held some time within the next year, if this measure was introduced before the election there would appear to be limited lead time to ... educate the public on what is expected of them," the committee's scrutiny report says.
"As such, it is not clear if it may in fact reduce public confidence in the electoral system and discourage some voters from voting."
The committee said it also remained unclear how the laws would actually protect against voter fraud, how they would prevent people voting a number of times at different locations and whether the government looked at the impact on voter turnout.
The committee has asked the government to clarify evidence on why the laws are necessary, whether it will disproportionately hurt particular groups and whether it had considered any less restrictive alternatives.
Labor senator Don Farrell has said the tens of thousands of people who would be denied a vote far outweighed the 2000 people who voted twice, mostly by accident.
"(The government) are not interested in cleaning up fraud ... they want to suppress votes."
The laws face an uphill battle in the Senate with key crossbenchers raising concerns about the speed at which the government is trying to push them through.
South Australian senator Rex Patrick says the government does not have his support and he is sceptical of the laws after receiving a government briefing where voter fraud was described as "not a problem".
With One Nation in support of the reform, and Labor and the Greens opposed to it, the government will now need a vote from either independent Jacqui Lambie or Centre Alliance's Stirling Griff to pass the legislation.
But the government will need both votes if LNP senator Gerard Rennick holds firm on his commitment to withhold his vote in the Senate entirely until the government meets a list of demands centred around vaccination mandates and travel restrictions.