Bishop queries retrospective laws

Foreign Minister Julie Bishop says she doesn't support laws being made retrospective as a matter of principle.

But Ms Bishop said there "may well be circumstances" where retrospectivity could apply, such as in relation to proposed new laws stripping citizenship from terrorism suspects.

"As a matter of principle, I wouldn't support retrospectivity. However, we would need to look at the number of convicted terrorists and what their citizenship status was before we could make a definitive statement on that," she told reporters in Perth on Friday.