The Australian migration zone covers such
Australian controlled territories as the government may determine. Prior to 2001, the Australian migration zone consisted of the mainland, as well as some
external territories.
Norfolk Island, for example, was not part of the Australian migration zone until 2016. Under Australia's universal visa policy, a non-
citizen must hold an Australian visa within the Australian migration zone. Without such a visa, or a
bridging visa, the non-citizen is an unlawful non-citizen and treated as an "
unauthorised arrival". However, the main effect of the migration zone is that unauthorised arrivals outside the zone have very limited access for review by
Australian courts. In the Australian government’s strategy to stem the
flow of unauthorised arrivals into Australia, in September 2001, the government passed the
Migration Amendment (Excision from Migration Zone) Act 2001 and the
Migration Amendment (Excision from Migration Zone) (Consequential Provisions) Act 2001 which removed ("excised") a number of external territories from the Australian migration zone. The excised territories included
Ashmore,
Cartier,
Christmas and
Cocos Islands, which lie in the Indian Ocean between Indonesia and Australia. The effect of the change was to limit the ability of unauthorised arrivals arriving there, termed "offshore entry persons", to apply for a visa on arrival. However, the Minister was still empowered to grant a visa to such persons “in the public interest”. In 2010, a landmark
High Court ruled that the processing procedures on Christmas Island were unlawful and unconstitutional. After these territories were excised, increasing numbers of asylum seekers attempted to reach the Australian mainland by-passing those islands. To combat this tactic, on 30 October 2012, the Australian government excised the entire Australian mainland from the Australian migration zone. The objective of the change was to limit
judicial review for boat arrivals. Before the excise, asylum seekers who reached the mainland by boat could not be sent for immigration processing to offshore
Australian immigration detention facilities on
Nauru or Papua New Guinea's
Manus Island. The excising of islands from the Australian migration zone was and remains a controversial aspect of
Australian immigration policy. Refugee advocates argue that Australia is not meeting its obligations under international law to protect refugees. This was not accepted by the
Howard government, which contended that international law obliged Australia to provide temporary protection only and not necessarily permanent settlement. ==Effect on unauthorised arrivals==