Heathrow airport is urging the UK government to ensure minimal disruption amid a slot usage review warning it could impact passenger choice and international connectivity.

Airport Coordination Limited (ACL), the independent body which manages slot allocation, is conducting the review with a specific focus on the ‘use it or lose it’ rule.

This currently allows an airline to retain a slot if it operates flights at least 80% of the time. Heathrow is asking the government retains the current 80:20 rule to ensure consistency for passengers.

Heathrow fears alterations to the current set up could result in instability and missed opportunities for enhanced international connectivity.

Alyson Playford, Aviation Director at Heathrow, said: “Providing choice and stability for our passengers are our key priorities, and by retaining the 80:20 slot ratio and clarifying “Justified Non-Use of Slots” regulation, these priorities can be delivered.

“We urge the Government to consider our asks, and not to diverge too heavily from the Worldwide Airport Slot Guidelines and international best practice.”

Slot allocation at Heathrow is a key tool for managing capacity effectively and efficiently and, due to constrained capacity and high volume of traffic, they are highly sought after.

Heathrow wants to see current ratios retained to reduce flight cancellations, improve stability for passengers, and enable the introduction of new routes for consumers long-term.

The airport is also asking for clarifications to the “Justified Non-Use of Slots” (‘JNUS’) regulation to enable airlines to hand back slots they will not use earlier than they can today.

The JNUS rules can give exemptions to the 80:20 slot usage ratio by allowing airlines to justify non-utilisation of allocated slots, when there have been unforeseeable and unavoidable circumstances outside the air carrier’s control, for instance, extreme weather conditions or airspace closure.

Strengthened monitoring rules will also prevent airlines from holding onto slots they do not intend to use, ensuring optimal use of slots by other airlines and cargo carriers as well as stability and choice for passengers.