Airport slot alleviation returns: what the Gatwick judicial review means for airlines

The resilience of the aviation industry has been tested repeatedly over the past six years. The Covid-19 pandemic and, more recently, the conflict in the Middle East have disrupted airline operations on a global scale. Although very different events, both prompted the UK Government to relax the normal airport slot rules and provide airlines with greater operational flexibility.

The English High Court’s recent decision in R (Gatwick Airport Ltd) v Secretary of State for Transport & Others [2026] EWHC 1733 (Admin) confirms the lawfulness of the latest round of slot alleviation measures. More importantly, it suggests that slot alleviation is no longer an exceptional Covid-era measure but an established part of the UK's regulatory toolkit when major external events disrupt airline operations.

From Covid-19 to the conflict in the Middle East

Under the UK's slot allocation regime, airlines operating at Level 3 (coordinated) airports, including Heathrow, Gatwick, Stansted and Manchester, are generally required to use at least 80% of their allocated slots during a scheduling season to preserve historic rights in the equivalent season the following year. This is the familiar ‘use it or lose it’, or ’80:20’ rule, set out in UK Regulation 95/93 on common rules for the allocation of slots at UK airports, and derived ultimately from EU law.

During the Covid-19 pandemic, widespread travel restrictions and the collapse in passenger demand made compliance with those utilisation requirements impossible for many carriers. In response, the UK introduced a series of slot alleviation measures over multiple IATA scheduling seasons, suspending or relaxing the normal usage requirements. These effectively mirrored equivalent measures passed by the EU at around the same time. The objective in both cases was clear: to avoid airlines operating empty or near-empty ‘ghost flights’ simply to preserve their historic rights to the slots.

The Airports Slot Allocation (Alleviation of Usage Requirements) Regulations 2026 (2026 Regulations) marked the first significant return to slot alleviation by the UK since the pandemic. The continuing conflict in the Middle East has resulted in airspace restrictions, longer routings, increased fuel costs and changes in passenger demand on affected markets. The UK Government concluded that these operational pressures justified a targeted intervention. By contrast, the European Commission has so far declined to take similar action.

The 2026 Regulations allow airlines to hand back up to 10% of their allocated slots during the IATA Northern Summer 2026 (NS26) and Northern Winter 2026 (NW26/27) scheduling seasons without losing historic entitlement to those slots. The 2026 Regulations came into force on 19 June 2026.

The regulatory response was not limited to legislation. In May, the UK slots coordinator, Airport Coordination Limited (ACL), issued guidance setting out the process for claiming the additional alleviation, including the conditions for slot returns and the treatment of those cancellations for utilisation and historic entitlement purposes.

The challenge brought by Gatwick Airport

Gatwick Airport Limited sought judicial review of the 2026 Regulations shortly after they were introduced and before key slot hand-back deadlines expired.

Gatwick initially sought interim relief to suspend the 2026 Regulations, but the application was later abandoned and the claim proceeded to an expedited rolled-up hearing. British Airways, TUI Airways and IATA intervened as interested parties, reflecting the significance of the 2026 Regulations for airlines operating at coordinated UK airports and the wider airline industry's interest in preserving operational flexibility during periods of disruption.

Gatwick argued, among other things, that the Secretary of State had acted outside the powers conferred by section 14 of the Retained EU Law (Revocation and Reform) Act 2023 (REUL Act). In particular, it contended that the 2026 Regulations failed to satisfy the statutory requirement that changes made under the REUL Act should not increase the overall regulatory burden and that the Secretary of State had not lawfully concluded that this condition was met. It also challenged the adequacy of the consultation process undertaken before the 2026 Regulations were adopted, including the four-day consultation period.

The Court granted permission on Gatwick's principal grounds of challenge but ultimately dismissed the claim. In summary, the Court concluded that:

• The Secretary of State acted within the scope of the statutory powers contained in the REUL Act and was entitled to conclude that the temporary hand-back mechanism did not increase the regulatory burden in a manner that rendered the 2026 Regulations unlawful.
• The 2026 Regulations created a voluntary and time-limited scheme, allowing airlines to return a limited proportion of their slots while retaining historic rights, rather than imposing additional obligations on airports or airlines.
• The consultation process was lawful, notwithstanding its limited duration. The Court accepted that the UK Government was operating under exceptional time pressure given the imminent slot hand-back deadlines and the impending expiry of the statutory power under which the 2026 Regulations were made.
• The UK Government was entitled to exercise a broad margin of judgment when assessing the operational challenges facing the aviation sector arising from continuing disruption in the Middle East.

Notably, the proceedings moved at exceptional speed. The claim was issued on the same day the 2026 Regulations were made (17 June), heard on an expedited basis (7 July) and determined before the first hand-back deadline expired (9 July), giving airlines certainty as to whether they could rely upon the alleviation measures.

What does this mean for airlines operating to and from the UK?

The most significant aspect of the judgment is that the High Court has effectively endorsed the use of slot alleviation as a legitimate policy response to aviation disruption beyond the context of Covid-19.

Future crises may look very different – whether geopolitical instability, airspace closures, fuel supply issues or other operational shocks – but the judgment suggests that temporary slot alleviation measures are likely to remain available where airlines face significant operational disruption. The courts are also likely to afford the UK Government a significant degree of latitude when responding to such events. For airlines, that provides reassurance that policymakers remain willing to intervene when necessary. For airports, it is a reminder that the balance between efficient capacity utilisation and operational flexibility will continue to be contested.

Slot alleviation should therefore no longer be viewed as a Covid-era anomaly but as an established feature of the UK's response to major aviation disruption.