27.
82 The consequence of this manoeuvring by the Commonwealth was that AZC20's liberty following the order of Kennett J for habeas corpus was precarious. If the decision of the primary judge were upheld in ASF17's appeal then AZC20 would be liable to be redetained. But the discontinuance by the Commonwealth of its appeal from the decision of Kennett J meant that AZC20 would be denied the right of making submissions in an appeal which challenged the reasoning of Kennett J. On 15 February 2024, the solicitors for AZC20 therefore wrote to the Commonwealth seeking a written assurance that AZC20 would not be redetained based upon any reasoning of the Full Court of the Federal Court in ASF17's appeal. No assurance was provided. Instead, on 15 February 2024, the Commonwealth applied to remove ASF17's appeal into this Court. That application was granted on 23 February 2024.
83 AZC20 properly accepted that his "interests" (his "rights against or liabilities to any party to the action in respect of the subject matter of the action"[1]) will not be directly affected by any orders in this appeal. But there is a discretion to grant intervention where a person's rights or liabilities will be indirectly, but "substantially", affected by the orders made.[2] "Substantially" is one of those weasel words that concede the impossibility of any formula which could apply in every circumstance to distinguish those persons for whom the precedential effect of a decision will never be sufficient to allow intervention from those for whom it might be sufficient.
84 There is no doubt that AZC20's "interests" will be substantially affected by the orders of this Court. The liberty of AZC20 to remain in the Australian community under his temporary bridging visa may depend upon there being no change to the basis upon which the order for habeas corpus was granted by Kennett J. The discontinuance of the Commonwealth's appeal from the orders of Kennett J means that without intervention AZC20 would be denied the ability to defend his interests in an appeal where the reasoning of Kennett J was challenged. In addition, the high quality of AZC20's submissions demonstrated that they were likely to be of assistance to this Court. For those reasons, I joined in the exercise of discretion to grant leave to AZC20 to intervene by making both written and oral submissions.
Application of the first requirement to this appeal
The logic of ASF17's primary submission
85 ASF17's primary submission was that the inescapable logic of the reasons of six members of this Court in NZYQ required that he be granted an order for
