Australian lawyers are concerned that low-level criminals and people participating in religious festivals could soon be rendered stateless under tough new citizenship laws aimed at terrorists.
The Morrison government wants to be able to deport Australian-born extremists who are entitled to citizenship in another country.
But the Law Council of Australia fears the citizenship-stripping powers are disproportionately harsh and could potentially leave people stateless, in breach of international law.
Australians can already lose citizenship if they are sentenced to at least six years in prison for terror offences, and have citizenship of another country.
The proposed new powers would allow the Home Affairs minister to strip citizenship from anyone convicted of terror charges, regardless of the length of their sentence.
The Law Council's David Neal will front a parliamentary inquiry examining the bill in Canberra on Wednesday, urging federal lawmakers to keep the six-year threshold in place.
"Low-level offending, which is dealt with to finality in a local court, could be captured by laws that lead to citizenship cessation," he will say, according to an advanced copy of his opening statement.
Dr Neal is also concerned the offence of "associating with a terrorist organisation" would be captured by the bill.
"This would give rise to the risk that a person could lose their citizenship for an offence which potentially captures a range of legitimate activities, such as participating in some social and religious festivals and gatherings," he will say.
The laws would also allow a minister to strip Australian citizenship from a convicted terrorist if "reasonably satisfied" they may be entitled to foreign citizenship in another country, lowering the threshold significantly.
"As recent history demonstrates - in both the cases of members of parliament and the (Neil) Prakash case - determining existing foreign citizenship can be difficult," Dr Neal will say.
"Determinations based on predictions about future foreign citizenship - which may include decisions by foreign governments - are obviously fraught."
The Morrison government picked a diplomatic fight with Fiji over the summer break after stripping terrorist Prakash of his Australian citizenship.
Prakash was born in Melbourne to a Fijian father but Fiji says he is not a citizen.
The federal government has indicated dual nationals who are stripped of their citizenship could languish indefinitely in immigration detention if other countries refuse to take them back.
