The Australian High Court’s verdict, has dealt “another death blow to the federal government’s plans to give asylum seekers temporary protection visas [and has] set significant new limits on Australia’s policy of mandatory detention,” reports The Guardian.

The decision will throw into doubt the legality of detention of thousands of people in Australia, potentially spelling the end for Australia’s mandatory detention regime as we know it, notes the report.

“In the unanimous decision handed down on Thursday, the court threw out the federal government’s strategy of granting temporary visas to asylum seekers through a legal loophole. Unable to get temporary protection visas through parliament, the federal government had been granting other temporary visas which blocked asylum seekers from applying for permanent visas, but Thursday’s case ruled against that practice.”

More importantly, and for the first time, the court clearly set out the constitutional limits on immigration detention. It was previously unclear for what purposes the government could detain non-citizens. The court has now clearly stated that the government can lawfully detain someone in only three circumstances:

• to consider whether to let someone apply for a visa;
• to consider an application for a visa;
• or to remove someone.

Detention is only lawful if these purposes are being “pursued and carried into effect as soon as reasonably practicable”, the court held. The length of detention must be assessed by what is “necessary and incidental” to execute and fulfil those purposes. These limits on detention are constitutional. In other words, parliament cannot override them by introducing new legislation.