ACT Labor will not support a Greens' bill to lower the ACT's voting age to 16, saying it would undermine compulsory voting and could discourage participation.
Greens' backbenchers Johnathan Davis and Andrew Braddock will bring the bill on for debate next week, despite an inquiry recommending the bill not pass.
Mr Davis said, in a statement on Friday, they did not know how the Labor members of the Legislative Assembly and "it's time to find out".
But Special Minister of State Chris Steel has confirmed Labor does not support the Greens' bill. He said the bill threatened the principle of compulsory voting.
"A strong democracy depends on all citizens being able to participate equally. It's why our nation has a deeply held principle of compulsory voting," he said.
"Labor believes it's a cornerstone of Australian democracy and it's why we have fiercely protected our system of compulsory voting in this country that has existed since 1924.
"That principle is, that if you have the right and privilege to vote, it is your responsibility to do so."
The Canberra Liberals will also not support the bill.
The Greens will put forward amendments to their bill when it is debated.
The Greens' original bill proposed to lower the fine for those who don't vote from $20 to $10 in an attempt to make it more affordable for young people.
But the bill will be amended so that first-time voters would receive a warning if they fail to vote.
Mr Steel said Labor did not agree with either approach. He said it was unfair to penalise minors who did not vote and likened a warning to voluntary voting.
"The Greens' proposal to issue warnings for not voting would effectively introduce a system of voluntary voting in the ACT," he said.
"It would create two classes of voters with different rules, an unequal system, where some people have to vote and some people don't have to.
"We think that fundamentally undermines equality in our voting system and the objective of compulsory voting to ensure representation and participation in democracy."
Mr Steel said the proposed warning could result in young people's participation being lower.
"With no penalties applying, young people's participation would likely be lower than other age groups, undermining the objective of compulsory voting of achieving greater participation," he said.
"But it would also undermine the objective of ensuring that elected representatives and their policies reflect the mandate of as greater populace as possible of eligible voters.
"If only one section of young people vote, that is unequal; it does not reflect the whole group of young people."
The Greens' bill would only apply to ACT elections.
