Mzapc and Minister for Immigration And Border Protection

This case concerns an application for special leave to appeal to the High Court of Australia, brought by the applicant, Mzapc, against the Minister for Immigration and Border Protection. The dispute centres on whether the Federal Court correctly applied principles of jurisdictional error, particularly concerning the materiality of undisclosed information and the onus of proof in establishing such materiality. The applicant contends that the majority judgment in *SZMTA* represents a departure from established jurisprudence regarding jurisdictional error, requiring correction or clarification by the High Court.

The legal issues before the Court involve two primary questions. The first concerns the role of materiality in determining a claim of jurisdictional error, including the onus of proof for materiality once jurisdictional error is established, and the presumption of regularity in decision-making processes found to be irregular. The second question relates to the Federal Court's approach to credibility, specifically whether only offences of overt dishonesty, as opposed to those involving implicit misrepresentation or disregard for authority, can impact an applicant's credibility and reliability.

The applicant argued that the conventional understanding of materiality, as established in *Stead v State Government Insurance Commission*, requires a respondent to demonstrate that undisclosed information could not have made a difference to the outcome. This contrasts with the applicant's submission that the majority in *SZMTA* inverted this process, placing an onus on the applicant to prove materiality, effectively requiring them to delve into the decision-maker's mind and elevating the standard of proof. The applicant also challenged the presumption of regularity applied by the primary judge, arguing it was illogical to infer regularity from an established irregularity. The respondent contended that the approach in *SZMTA* was consistent with the legislation and that the applicant faced a difficult, but not impossible, task in proving materiality, particularly in the specific context of section 438 notifications under the Migration Act. The respondent further argued that *CNY17* was distinguishable due to its focus on apprehended bias and a different statutory framework.