Commercial Litigation Australia 2026: Interlocutory Injunctions & Urgent Relief

A spate of early-2026 Federal Court interlocutory decisions, most notably in pharmaceutical patent disputes, has sharpened the focus on urgent injunctive relief as a critical tool in commercial litigation Australia practitioners must master. For general counsel, directors and insolvency practitioners, the question is no longer academic: the Court has demonstrated a renewed willingness to grant preliminary injunctions where the evidence and undertakings warrant it. This practitioner playbook explains the legal tests, procedural mechanics and tactical steps involved in seeking or opposing interlocutory injunctions in the Federal Court, grounded in the latest practice notes and 2025–26 case law.

Whether you are protecting market exclusivity, preserving assets ahead of insolvency, or defending against an urgent restraint, the framework below provides a decision-ready guide to every stage of the process.

Executive Summary and Key Takeaways

Before committing to an urgent interlocutory application, or marshalling a defence against one, decision-makers should pressure-test five critical questions:

• Strength of the prima facie case. Can you demonstrate a sufficient likelihood of success at trial to justify the Court’s intervention now? The threshold is not proof on the balance of probabilities, but it must be more than a mere assertion.
• Irreparable harm and the balance of convenience. Would damages at trial be an adequate remedy, or will the harm be irreversible, lost market share, destroyed evidence, dissipated assets, if interim relief is refused?
• Ability to give the usual undertaking as to damages. The Federal Court requires the applicant to submit to the usual undertaking, and the financial exposure can be substantial. Assess whether your client can satisfy the Court on this point.
• Procedural readiness. Duty judge listings move fast. Evidence must be in affidavit form, proposed orders must be drafted, and the registrar must be contacted before you arrive at the door of the Court.
• Pathway to expedited trial. Industry observers expect that courts will increasingly weigh the availability of a fast final hearing when deciding whether interim restraint is proportionate. Propose a realistic timetable.

The sections that follow unpack each element in detail, with checklists, case studies and a practical opposition playbook.

Commercial Context: Why Interlocutory Relief Matters in Commercial Litigation Australia (2026)

Australia’s commercial litigation landscape is characterised by high-value disputes across intellectual property, insolvency, competition, and contractual enforcement. The Federal Court of Australia handles the bulk of patent, trade mark and competition matters, while state Supreme Courts exercise parallel jurisdiction over commercial injunctions and asset preservation. For businesses operating in regulated markets, pharmaceuticals, financial services, resources, the commercial consequences of delay can dwarf the cost of the litigation itself.

The early months of 2026 brought this into sharp relief. The Federal Court granted interlocutory injunctions in two significant pharmaceutical patent disputes, AstraZeneca AB v Pharmacor Pty Ltd [2026] FCA 88 and, in late 2025, Janssen Pharmaceutica NV v Juno Pharmaceuticals Pty Ltd [2025] FCA 1538, marking a notable shift after years in which originator patentees struggled to obtain preliminary injunctive relief. Practitioner commentary described the development as “the balance shifting” in favour of patentees willing to meet the Court’s evidentiary and undertaking requirements.

Beyond pharma, the same interlocutory toolkit, injunctions, freezing orders, search orders and expedited hearings, applies across all sectors of commercial litigation Australia businesses encounter. Creditors facing asset dissipation, franchisors restraining departing franchisees, and technology companies protecting trade secrets all rely on the same Federal Court practice notes and the same legal test. The 2026 pharma decisions are best understood not as niche IP rulings, but as a recalibration of general interlocutory principles that strengthens the hand of any well-prepared applicant.

What Is an Interlocutory Injunction? The Federal Court Interlocutory Test

An interlocutory injunction is a court order that preserves the status quo, or prevents imminent wrongful conduct, pending the final determination of a dispute. It is, by design, a temporary measure. The Federal Court’s power to grant interlocutory relief derives from section 23 of the Federal Court of Australia Act 1976 (Cth) and, in patent matters, from the statutory framework of the Patents Act 1990 (Cth). The test applied by the Federal Court follows the principles established in Australian Broadcasting Corporation v O’Neill (2006) 227 CLR 57, which adapted the American Cyanamid framework for Australian conditions.

The Prima Facie Case: Evidence Standard

The applicant must demonstrate that there is a “serious question to be tried” or, equivalently, that the claim is not frivolous or vexatious. In practice, this requires evidence, typically by affidavit, that establishes a sufficient likelihood of success at final hearing. The Court does not conduct a mini-trial, but it will scrutinise the strength of the underlying cause of action, the quality of the evidence and any obvious defences. In patent cases such as AstraZeneca v Pharmacor, this meant demonstrating that the asserted patent claims were valid and infringed, supported by expert evidence. The stronger the prima facie case, the less the balance of convenience needs to favour the applicant.

Balance of Convenience and Public Interest

The balance of convenience inquiry asks whether the applicant will suffer greater harm from refusal of the injunction than the respondent will suffer from its grant. Relevant factors include the quantifiability of loss, the impact on third parties and, in appropriate cases, the public interest. In pharmaceutical matters, the Court has considered the effect of generic entry on PBS (Pharmaceutical Benefits Scheme) pricing, once a generic is listed, the statutory price reduction is typically irreversible, making damages an inadequate remedy for the originator. This reasoning featured prominently in both the AstraZeneca and Janssen decisions and represents a factor that industry observers expect will continue to weigh heavily in future pharma interlocutory applications.

Undertaking as to Damages: Form and Risk

The Federal Court’s Practice Note GPN-UNDR sets out the form and consequences of the “usual undertaking as to damages. ” An applicant for interlocutory relief must undertake to submit to such order as the Court may consider just for the payment of compensation to any person affected by the operation of the interlocutory order, should the Court later find that the order should not have been made. This is not a formality: the undertaking exposes the applicant to potentially significant liability if the case ultimately fails. The Court may require evidence of the applicant’s capacity to meet the undertaking, and a corporate applicant’s financial position will be examined.

Practitioners should advise clients on the quantum of potential exposure before filing and ensure that the undertaking wording complies with GPN-UNDR.

Urgent Applications and Federal Court Practice Notes: Commercial Litigation Australia Procedures

The Federal Court’s practice note framework governs the mechanics of urgent interlocutory applications. Three practice notes are essential reading for any practitioner in this space: GPN-DUTY (Duty / Urgent Applications), GPN-UNDR (Usual Undertaking as to Damages), and the practice notes governing freezing orders (GPN-FRZG) and search orders (GPN-SRCH). These are published on the Federal Court’s practice notes index.

Getting a Duty (Urgent) Listing: Step by Step

Under GPN-DUTY, which operates as an interim practice note during the Federal Court’s three-region trial of its National Court Framework, parties seeking urgent interlocutory relief must follow a structured process:

• Contact the registry. The applicant’s solicitor must contact the relevant registry by telephone or email, explaining the nature and urgency of the application. The registrar will assess whether the matter qualifies for a duty listing.
• File the application and supporting affidavits. All material must be in proper form before the duty judge will hear the matter. Draft proposed orders must accompany the application.
• Notify the respondent. Except in genuinely ex parte cases (such as search orders), the applicant is expected to give the respondent reasonable notice. The Court takes a dim view of ambush tactics.
• Appear before the duty judge. The duty judge will hear the application, typically within one to two business days of the registry being contacted. In cases of extreme urgency, same-day listings are available.

The table below summarises the key types of urgent interlocutory relief available through the Federal Court duty list:

Freezing and Search Orders: Forms and Annexures

Applications for freezing orders and search orders are governed by dedicated practice notes, GPN-FRZG and GPN-SRCH respectively, which prescribe the form of order, mandatory annexures and the obligations of the applicant and any independent solicitor. Freezing orders require the applicant to demonstrate a good arguable case on the underlying claim and a real risk that assets will be dissipated. The prescribed form of order includes undertakings by the applicant as to damages and as to the payment of the respondent’s reasonable costs of complying with the order.

Search orders are among the most intrusive remedies available and are granted only where there is a strong prima facie case, serious potential or actual loss, and clear evidence that the respondent possesses relevant documents or things and that there is a real possibility of destruction.

Practical Pre-Application Steps: Asset Preservation, Evidence and Relief Drafting

Preparation is everything in urgent interlocutory proceedings. The duty judge will expect a polished, complete application supported by cogent evidence. The following checklist and evidence matrix are designed for general counsel and instructing solicitors preparing an urgent application in commercial litigation Australia disputes.

Immediate 10-Point Pre-Application Checklist

Evidence Matrix: What to Attach to the Affidavit

The quality of the supporting evidence is often decisive. Courts have consistently emphasised that interlocutory relief is an extraordinary remedy, and applicants who present incomplete or poorly organised material risk not only refusal but adverse costs orders. Every exhibit should be clearly referenced in the body of the affidavit, paginated, and cross-referenced to the proposed orders.

Case Studies and Precedent Lessons: Interlocutory Relief Case Law 2025–26

The 2025–26 decisions in pharmaceutical patent disputes provide the most instructive recent examples of the Federal Court interlocutory test in action. While these are patent cases, the principles and judicial reasoning apply with equal force across all areas of commercial litigation Australia courts adjudicate.

AstraZeneca AB v Pharmacor Pty Ltd [2026] FCA 88. The Federal Court granted an interlocutory injunction restraining Pharmacor from launching a generic version of AstraZeneca’s dapagliflozin product pending trial. The Court found a strong prima facie case of patent infringement, held that the balance of convenience favoured the patentee, in part because PBS price reductions triggered by generic entry would be practically irreversible, and was satisfied with the undertaking as to damages. Practitioner commentary described the decision as the first time in several years that a pharmaceutical patentee had successfully obtained a preliminary injunction, signalling that “the balance has shifted.”

Janssen Pharmaceutica NV v Juno Pharmaceuticals Pty Ltd [2025] FCA 1538. Decided in late 2025, this case saw the Federal Court grant an interlocutory injunction in another pharmaceutical patent dispute. The reasoning followed similar lines: a robust prima facie case, coupled with evidence that damages would be an inadequate remedy given the structural effects of generic entry on regulated drug pricing. The decision was widely noted as reinforcing the trend established in subsequent months by the AstraZeneca ruling.

Lessons for Originators and Applicants

• Invest in evidence quality. Both successful applications were supported by detailed expert evidence on patent validity, infringement and market impact modelling. The Court was willing to act on strong affidavit material.
• Address the undertaking head-on. Applicants who proactively demonstrate financial capacity to honour the usual undertaking as to damages remove a significant obstacle to relief.
• Propose a realistic trial timetable. Early indications suggest that courts are more willing to grant interim relief when the applicant simultaneously proposes an expedited path to final hearing, reducing the duration for which the respondent is restrained.

Lessons for Generics and Defendants

• Challenge the prima facie case vigorously. Where the patent is vulnerable to invalidity arguments or the infringement case is thin, invest in responsive expert evidence. The Court’s willingness to grant relief correlates directly with the perceived strength of the applicant’s case.
• Quantify the applicant’s damages. If damages can be shown to be calculable and the applicant’s loss is compensable in money, the balance of convenience may tilt against interim relief. Prepare a responsive financial affidavit.
• Scrutinise the undertaking. If the applicant lacks the financial capacity to honour the undertaking, this is a powerful ground of opposition. Seek discovery of the applicant’s financial position.
• Offer interim arrangements. Consider proposing alternatives to a full injunction, for example, an undertaking not to launch pending an expedited trial, a keep-account arrangement, or an escrow of profits. Courts value pragmatism and may prefer a negotiated interim regime to a contested injunction hearing.

How to Oppose an Urgent Application: Practical Defence Playbook

Respondents served with an urgent interlocutory application face compressed timeframes and high stakes. The following tactical framework applies across all categories of commercial litigation Australia respondents may face, from patent injunctions to freezing orders.

• Assess the application immediately. Identify the legal test being invoked, the proposed orders, and the return date. Determine whether you have time to file responsive evidence or must seek an adjournment.
• Challenge the prima facie case. File affidavit evidence and, where appropriate, expert reports that expose weaknesses in the applicant’s case, invalidity, non-infringement, absence of the asserted right, or the availability of a complete defence.
• Attack the balance of convenience. Demonstrate that the applicant’s loss is quantifiable in money (and therefore compensable by damages at trial), that the injunction would cause disproportionate harm to the respondent or third parties, and that the public interest does not favour interim restraint.
• Scrutinise the undertaking as to damages. Request evidence of the applicant’s financial position. If the undertaking is inadequately supported, submit that the Court should not grant relief without proper security.
• Propose alternatives. Offer undertakings, escrow arrangements or consent to an expedited trial timetable. Courts strongly favour parties who propose constructive interim solutions rather than simply resisting.
• Apply to vary or discharge. If a freezing order or injunction has been granted ex parte or on short notice, prepare a prompt application to vary or discharge the order, supported by full evidence.

Timing is critical. The duty judge will expect the respondent to engage substantively at the first return date. A respondent who appears without evidence and without a coherent position risks the application being determined in its absence. Prepare a responsive affidavit, even a short one, addressing the key contested issues, and have counsel ready to make oral submissions on the balance of convenience.

Timetabling, Expedited Hearings 2026 and Cost-Risk Management

An interlocutory injunction is not an end in itself, it is a bridge to final hearing. The Federal Court’s docket system and the reforms being trialled under the National Court Framework are designed to move matters to resolution efficiently. Practitioners should leverage this by proposing a timetable to trial at the same time as seeking (or opposing) interlocutory relief.

Expedited trial timetables are particularly important in the current environment. The likely practical effect of the 2025–26 pharma decisions is that courts will expect applicants to demonstrate not only that interim relief is justified, but that they are committed to a prompt final determination. A proposed timetable that compresses discovery, evidence and trial preparation into a realistic but accelerated window will strengthen any interlocutory application.

Cost-risk management is equally critical. The costs of an urgent interlocutory application, including the preparation of affidavit evidence, expert reports, counsel’s fees and the hearing itself, can be substantial. Decision-makers should model the cost of the interlocutory phase against the value of the interim relief sought, the risk of an adverse costs order if the application fails, and the potential liability under the usual undertaking as to damages. In insolvency-adjacent disputes, the calculus may also involve the question of whether asset preservation injunctions or the appointment of a receiver is the more proportionate response. Where assets are at genuine risk of dissipation, a freezing order coupled with an expedited trial may be more effective, and less costly, than receivership.

Conclusion: Practical Checklist for Urgent Interlocutory Relief in Commercial Litigation Australia

The resurgence of interlocutory injunctive relief in the Federal Court in 2025–26 confirms that the remedy is alive, available and potent, for applicants who prepare meticulously and for respondents who engage strategically. The following 12-step checklist distils the key decision points covered in this guide:

1. Identify the cause of action and confirm jurisdiction.
2. Assess the strength of the prima facie case, honestly.
3. Quantify the harm and confirm that damages are not an adequate remedy.
4. Evaluate the balance of convenience, including third-party and public interest factors.
5. Model the financial exposure under the usual undertaking as to damages (GPN-UNDR).
6. Gather and preserve evidence immediately, engage forensic IT if evidence destruction is a risk.
7. Prepare affidavits and expert reports in proper form.
8. Draft proposed orders in compliance with the relevant Federal Court practice note.
9. Contact the registry and request a duty (urgent) listing (GPN-DUTY).
10. Notify the respondent unless seeking genuinely ex parte relief.
11. Propose an expedited timetable to final hearing.
12. Brief counsel experienced in interlocutory applications, the duty judge hearing is fast-paced and unforgiving of poor preparation.

Interlocutory relief in commercial litigation Australia demands a combination of legal rigour, tactical judgment and procedural precision. The stakes are high, the timeframes are compressed, and the consequences of success or failure, for both sides, can define the outcome of the entire dispute.

This article is general guidance only and does not constitute legal advice. Readers should seek tailored professional advice in relation to their specific circumstances.

Sources

1. Federal Court of Australia, Practice Notes Index
2. Federal Court, Usual Undertaking as to Damages Practice Note (GPN-UNDR)
3. Federal Register of Legislation, Patents Act 1990 (Cth)
4. Federal Court of Australia, Judgments Index
5. Phillips Ormonde Fitzpatrick, “Has the Balance Shifted?”
6. Norton Rose Fulbright, “Balance Restored: Interlocutory Injunctions Granted for Pharma Patents”
7. King & Wood Mallesons Pulse, Federal Court Grants Urgent Interlocutory Injunction (Dapagliflozin)
8. Lexology, Interlocutory Injunctions Case Law Roundup