In immigration litigation, one question quietly shapes countless cases: When is a matter truly over?
Australia’s migration system is complex and multilayered, with decisions on visa refusals, cancellations, and protection applications often subject to merits review before the Administrative Review Tribunal (ART) and, in some instances, further scrutiny by the courts. This structure creates multiple avenues to challenge the same underlying decision, raising important questions about sequence, timing, and the scope of review. At the same time, the law recognises a counterbalancing principle: the need for finality. Doctrines such as res judicata, issue estoppel, and Anshun estoppel are designed to prevent parties from re‑litigating issues that have already been decided.
Yet, as this article explores, these doctrines operate in unusual and often narrow ways in the immigration sphere, particularly before administrative merits review bodies such as the Administrative Review Tribunal (ART), the primary body responsible for reviewing migration decisions. Courts have made it clear that while estoppel principles protect the integrity of judicial processes, they sit uneasily with the statutory design of the ART, whose task is not to apply legal technicalities but to arrive at the correct or preferable outcome. This article unpacks each doctrine, traces its application in migration law, and explains why – despite their intuitive appeal – these doctrines rarely prevent matters from being revisited before the ART.
Understanding the Doctrines
What Is Res Judicata?
Res judicata – Latin for “a matter judged” – is an umbrella doctrine that prevents re-litigation of matters already judicially resolved. It comprises three distinct estoppels:
- Cause of action estoppel (res judicata proper):
bars reassertion of rights or obligations already determined by a final judgment.
- Issue estoppel:
bars re-litigation of factual or legal issues necessarily determined in a prior judgment.
- Anshun estoppel:
bars raising claims that should have been brought earlier if it would have been unreasonable not to raise them.
While all three doctrines are well established in Australian law, their migration-specific application is nuanced and, in some contexts, deliberately limited.
Res Judicata Proper (Cause of Action Estoppel)
General Principles
Res judicata proper protects the finality of judicial determinations by preventing repeated challenges to the same cause of action. Dixon J in Blair v Curran[1] (Blair) famously distinguished it from issue estoppel:
- res judicata extinguishes the cause of action itself,
- issue estoppel prevents re-litigation of particular issues.
For cause of action estoppel to apply, three elements must be satisfied:[2]
- the cause of action must be identical to the earlier one;
- the parties or their privies must be the same; and
- the earlier judgment must be final and on the merits.
How Courts Apply It in Immigration Law
In Kong v Minister for Immigration,[3] the Federal Court held The Court held that res judicata applies to successive applications for judicial review if the cause of action is the same even if the grounds for jurisdictional error were different. Moreover, the Court further emphasised that the doctrine ensures decisiveness and finality in litigation upon judgement.
Similarly, in SZEVR v Minister for Immigration and Multicultural and Indigenous Affairs[4] (SZEVR), the Federal Magistrates Court explained that res judicata (and relatedly, issue estoppel) prevents a party from re-litigating a cause of action or issue that has already been finally determined by a court. The Court noted that for res judicata to apply, the factual circumstances, the substance of the proceedings, and the right to relief sought must be the same as in the earlier case. The Court also emphasised the importance of finality in legal proceedings.
This position was further reinforced in MZWKF v Minister for Immigration and Multicultural and Indigenous Affairs[5] (MZWKF), where the Court clarified that res judicata operates as a complete bar to subsequent claims where the same decision is challenged on the same grounds.
Limits to Res Judicata in Migration Matters
Courts have also emphasised important limits:
In SZHEW v Minister for Immigration and Citizenship[6] (SZHEW), the Federal Magistrates Court held that res judicata proper did not apply because the earlier decision was not a final judicial determination on the merits.
In Minister for Immigration, Local Government and Ethnic Affairs v Kurtovic[7] (Kurtovic), the Federal Court found that cause of action estoppel does not apply to the exercise of statutory discretion, such as deportation orders under the Migration Act 1958, as such powers may be exercised from time to time.
Similarly, in Comcare v Grimes,[8] the Federal Court held that cause of action estoppel should not generally apply to ART decisions due to their administrative (rather than judicial) nature and lack of finality.
Finally, in AIO21 v Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs,[9] the Court held that different grounds of jurisdictional error may constitute separate causes of action and are not barred by res judicata proper, distinguishing it from Anshun estoppel. These observations were obiter dicta.
Issue Estoppel
General Principles
Issue estoppel prevents re-litigation of issues of fact or law already determined by a final judgment. For issue estoppel to apply, the following criteria must be met:[10]
- the same issue was decided earlier;
- the earlier decision was final; and
- the parties are the same (or privies).
Unlike res judicata proper, issue estoppel may apply even when the cause of action differs, provided the issue in review was fundamental to the earlier judgment. Issue estoppel may also arise in the context of judicial review of administrative decisions in immigration law.[11]
Use in Immigration Proceedings
In immigration law, issue estoppel has been used to block repetitive judicial review grounds that replicate issues resolved in earlier litigation, taking Wong v Minister for Immigration and Multicultural and Indigenous Affairs[12] (Wong) for instance. Similarly, in Somanader v Minister for Immigration and Multicultural Affairs,[13] the Court held that issue estoppel barred the applicants from re-arguing issues previously and definitively determined, even where those decisions were made by consent.
Key Limitations
Courts have identified several constraints:
Issue estoppel applies only to issues that were essential to the earlier decision, not to incidental matters. Consequently, incidental or unimportant matters do not give rise to issue estoppel.[14]
In immigration law, its application is limited by public law principles. In Kurtovic,[15] the Federal Court held that issue estoppel is inappropriate where a statutory discretion may be exercised afresh in light of new evidence or circumstances.
Issue estoppel also requires a prior determination by a competent judicial body and generally does not apply to administrative decisions such as those of the AAT, which may reconsider matters.[16]
Further, issue estoppel does not bar new issues that were not previously determined.[17] Courts have been reluctant to recognise any discretion to depart from issue estoppel, and in Wong held that no special circumstances existed.
Anshun Estoppel
General Principles
Anshun estoppel, established in Port of Melbourne Authority v Anshun Pty Ltd[18], prevents parties from raising issues in later proceedings that could and should have been raised earlier.
The doctrine is grounded in policy considerations of finality, avoiding inconsistent judgments, and preventing misuse of judicial resources.
The key question is whether it was unreasonable for the party not to raise the issue in the earlier proceedings.
In Australian immigration law, Anshun estoppel has been applied in judicial review proceedings. It is distinct from res judicata and issue estoppel, as it focuses on the unreasonableness of the omission, rather than whether the issue was previously decided.[19]
Application in Migration Law
Anshun estoppel applies where an issue was so relevant to earlier proceedings that it was unreasonable not to raise it at that time. In SZHEW,[20] the Court held that Anshun estoppel did not apply because the issue had not been previously considered and the applicant was unrepresented. Courts have confirmed that Anshun estoppel applies in judicial review proceedings, including migration matters (Stuart v Sanderson[21]; Wong), to prevent abuse of process and repetitive litigation. However, courts may decline to apply the doctrine where special circumstances exist, such as psychological disability or lack of legal representation.[22]
Limits – Especially Before the ART
Although Anshun estoppel is broadly applied, including in immigration law, it is subject to important limitations. Courts may decline to apply the doctrine where special circumstances justify the failure to raise an issue earlier, such as lack of legal representation or the emergence of new evidence.
Anshun estoppel also does not apply where the later proceedings involve a different cause of action. In Spassked Pty Ltd v Commissioner of Taxation,[23] the Court held that the doctrine did not apply because the issues arose from different time periods and were not central to the earlier case. Further, Anshun estoppel generally does not apply to tribunal proceedings, which involve de novo merits review.
Implications
While res judicata, issue estoppel and Anshun estoppel operate robustly in judicial proceedings – particularly to protect courts from repetitive litigation – their force weakens dramatically in the administrative review context.
In immigration matters before the AAT and ART:
- cause of action estoppel generally does not apply;
- issue estoppel does not bind the tribunal; and
- Anshun estoppel applies only sparingly, if at all.
The ART’s function is to remake decisions afresh, informed by all relevant material, not to police previous findings through technical procedural doctrines. For practitioners and applicants alike, this means earlier litigation does not necessarily close the door before the tribunal – although courts will still use estoppel doctrines to curb abuse of judicial review.
Pease get in touch with Warlows Legal today with any queries regarding your immigration law matter.
[1] [1939] 62 CLR 464 at 532.
[2] Applicants M16 of 2004 v Minister for Immigration and Multicultural and Indigenous Affairs (2005) 148 FCR 46.
[3] (2011) 199 FCR 375.
[4] [2006] FMCA 270.
[5] [2005] FMCA 917.
[6] [2009] FCA 783.
[7] (1990) 21 FCR 193.
[8] (1994) 50 FCR 60.
[9] [2022] FCAFC 114.
[10] Blair v Curran [1939] 62 CLR 464.
[11] Wong v Minister for Immigration and Multicultural and Indigenous Affairs (2004) 81 ALD 109.
[12] (2004) 81 ALD 109.
[13] (2000) 63 ALD 670.
[14] Kurtovic.
[15] Kurtovic.
[16] Commonwealth of Australia v Snell (2019) 269 FCR 18.
[17] Wong.
[18] (1981) 147 CLR 589.
[19] Kurtovic.
[20] SZHEW.
[21] (2000) 100 FCR 150.
[22] SZAJB v Minister for Immigration and Citizenship (2008) 168 FCR 410.
[23] (2007) 165 FCR 484.
