A Labor MP has broken ranks with her party's support for draft laws stripping terror suspects of citizenship.
West Australian MP Melissa Parke says the bill before federal parliament is unconstitutional, despite some improvements made under parliamentary scrutiny.
"In my view the bill remains contrary to the rule of law and the principles of natural justice and as such should not be passed by parliament," she told the lower house on Monday.
The powers will mean dual citizens will have their citizenship revoked if they engage in terrorism conduct offshore or if they fled the country after committing an act onshore.
Ms Parke said the bill was "fundamentally wrong" and the government should not take away lightly or lazily a person's citizenship.
She said terrorism ranked low on the list of real dangers posed to the public.
"The purpose of this bill is simply to act tough to emphasise the issue of security, to inflate the threat posed to Australia and to Australians, and to reap the cynical political benefits of so doing."
Greens MP Adam Bandt also spoke against what he labelled a "Tony Abbott-era" bill.
He questioned whether someone willing to kill others and themselves is going to change their mind because of the threat of having their citizenship taken away.
"If you're prepared to kill yourself as you take out the lives of others around you, a law like this is going to do nothing," he told parliament.
"This is not going to make us safer. It is going to divide people and it's a bridge too far."
Labor MP Stephen Jones supports the bill, but said he was concerned about whether it was constitutionally sound - despite reassurances from the government.
He suggested following the lead of Canada, New Zealand and the US, where "the power is restrained by judicial steps".
