The idea was proposed by Immigration Minister Peter Dutton (who would have this power) and supported by the Prime Minister Tony Abbott.
This would effectively render people, suspected by the immigration minister of being terrorists, stateless.
This comes into the category of ideas that are so bad it is almost impossible to start explaining what is wrong with them.
In Australian politics, the beginning of this explanation is rapidly becoming:” Well, Tony Abbott supports it.”
We have a legal system in Australia that is perfectly capable of dealing with people accused of terrorism. We don’t need to hand that responsibility to politicians.