Australia's conservative government is warning that tough immigration policies could soften if the opposition wins elections.

The government's policy of sending migrants who try to reach Australian shores to Papua New Guinea and Nauru suffered a blow last month when Papua New Guinea's Supreme Court ruled that Australia's detention of asylum seekers on Manus Island was unconstitutional.

Australia Broadcasting Corp. reported Thursday that asylum seekers are being allowed conditional freedom to leave Manus Island on Papua New Guinea.

Australian Immigration Minister Peter Dutton singled out comments by opposition Labor candidates that the camps should be closed and said Australia's policies would soften if the Labor wins July 2 polls.

Dutton said Nauru had given migrants freedom of movement since October and Papua New Guinea is heading in the same direction.