Changed time limits for NSIP appeals to the Court of Appeal
Those working on Nationally Significant Infrastructure Projects (‘NSIPs’) will be familiar with Lord Banner’s Independent Review into legal challenges against NSIPs (Oct 2024) as well as the Government’s call for evidence on Lord Banner’s recommendations and the Government’s subsequent statement in January 2025 announcing the proposals which would be taken forward.
What some may have missed, however, is the additional procedural change not foreshadowed in these documents. As of 1 October 2025, an appellant seeking to appeal a decision of the High Court in an NSIP judicial review now has seven days from the decision to file an appellant’s notice and grounds of appeal with the Court of Appeal (though longer for the skeleton). This is a significant reduction from the usual 21-day period for appeals to the Court of Appeal.
The background
By way of background, Lord Banner was tasked with investigating the causes of legal challenges against NSIPs and to explore options to streamline existing processes. The proposals arising from that review focused on:
- An overhaul of the permission stage for NSIP judicial reviews by: (i) removing the paper permission stage; and (ii) removing the possibility of renewing a permission application before the Court of Appeal where the High Court judge has deemed it ‘totally without merit’.
- Introduction of non-mandatory case management conferences (‘CMCs’). The ongoing challenge to the expansion of Gatwick Airport is the first example of an NSIP challenge where the High Court ordered a CMC and subsequently ordered a rolled-up hearing.
- Formal designation of NSIP judicial reviews as ‘significant’ planning court claims.
- Working with the judiciary to introduce target timescales for NSIP judicial reviews in the Court of Appeal and Supreme Court. The proposals for the Court of Appeal were concerned with the timescales within which the court should: (i) determine permission to appeal applications once an appeal had been filed; and (ii) hear the substantive appeals where permission is granted.
Notably, the 21-day period for filing an appellant’s notice to the Court of Appeal was not picked up by Lord Banner nor the Government’s public documents as a reason for delaying NSIP projects or otherwise causing delays in the appeals process.
NSIP appeals
Nonetheless, by way of the 188th Update to the Practice Directions supplementing the Civil Procedure Rules, we now have a new paragraph 17.3 within Practice Direction 52D. This paragraph introduced the promised target timescales in the Court of Appeal for determining an application for permission to appeal (four weeks from the filing of the appellant’s notice) and the hearing of NSIP appeals (four months from the filing of the appellant’s notice).
But practitioners will want to note in particular the following amendments, which now apply across all NSIP appeals:
- The appellant’s notice (N161) must be filed within seven days of the decision being appealed.
- The appellant’s notice and the appellant’s skeleton argument must be served on the respondent within seven days of the appellant’s notice being sealed. At the same time, the appellant is to file a core bundle and serve a core bundle index on the respondent.
- The respondent may file and serve reasons why permission to appeal should not be granted within seven days of service of the appellant’s notice and skeleton argument.
There is no change to CPR r.52.13(4)-(5) by which a respondent must file a respondent’s notice within 14 days of being notified that the Court of Appeal has granted permission to appeal.
It should be noted that form N161, the Appellant’s notice, has not been updated to reflect the changes concerning filing of the Appellant’s skeleton argument. Section 7 still requires practitioners to confirm either that the skeleton is attached to the notice or will be provided within 14 days. As neither can truthfully be ticked, the best approach may be to use the table in Section 13 of the N161 to explain, by reference to PD 52D, why the skeleton has not been provided and when it will be filed.
Acting with speed
The considerably reduced timescales for the permission to appeal stage mean that legal teams for all parties in an NSIP judicial review will need to act with speed in taking instructions and preparing for an appeal if so advised as soon as judgment in the High Court is handed down. The period during which parties have access to the draft embargoed judgment will become all the more important, as it will offer clients and legal teams a few extra days to consider their options. Any party seeking to appeal may, depending on the circumstances, need to consider asking the High Court to exercise its power under CPR 52.12(2)(a) to direct a longer period within which to file the appellant’s notice.
It also means that those considering the biggest developments, which often give rise to the most complex legal issues, will have less time to formulate grounds of appeal than those dealing with development outside the NSIP regime. It is not obvious that restricting the time for formulation of grounds of appeal in NSIP cases will lead to better or swifter appellate litigation.
The first NSIP appeal affected by the new procedural rule is the ongoing challenge to the expansion of London Luton Airport. The question of timescales, including whether an extension of time should be granted, is due to be considered by the Court of Appeal next week at a 2-day rolled-up hearing. The Appellant residents’ association is represented by Estelle Dehon KC, Ruchi Parekh and Hannah Taylor, instructed by Leigh Day.
Picture credit: South Kyle wind farm. Image by Vattenfall. Onshore wind projects above 100mw are now within the NSIP regime – as of December 2025.
