New electoral laws in Australia that automatically enrol up to 1.5 million voters are seen as another example of federal Labor "rorting the roll" by Liberal frontbencher Christopher Pyne.
The Australian reported on Monday that an analysis of Newspoll surveys indicates the coalition's primary vote would slip by 1.5 percentage points if those eligible to vote, but not enrolled - mainly young people - were enrolled.
As many as a dozen Liberal and Nationals seats may be threatened if Labor and the Australian Greens mobilised the "youth vote", the paper said.
Mr Pyne said this was "the latest iteration" of Labor trying to get an advantage over the coalition.
"Rorting the roll is routine for the Labor Party," he told Sky News.
AAP reports Mr Pyne also said voters should be required to show identification for enrolment purposes.
"I think our roll has been far too loose for far too long," he said.
Labor backbencher Nick Champion said automatic enrolment made sense in a system of compulsory voting.
"You have got to ensure that everybody who is eligible to vote has an opportunity to vote," he told Sky News.