The chief executive of Ryanair says the airline will not be able to run its full summer schedule because of jet fuel shortages if the Strait of Hormuz remains closed.

In an interview with ITV News, chief executive Michael O’Leary said that if the war in Iran doesn’t end “by the end of April”, he expects European airlines to start cutting scheduled flights.

The Strait of Hormuz has been closed for 30 days. If it remains closed for 60 or 90 days, then we’re all facing an unknown scenario, and we are certainly looking at maybe having to cancel 5%–10% of flights through May, June and July,” he said.

O’Leary explained that airlines won’t be able to choose which routes to cancel - cuts will depend on which airports suffer fuel shortages.

He said he expects to have only a few days’ notice from jet fuel suppliers, making disruption hard to manage.

Despite that, he urged passengers to book summer holidays “as quickly as they can”.

He insisted that most flights will operate and warned that delaying booking is more likely to mean paying higher prices as airfares rise.

According to data analytics firm Kpler, 18.8 million tonnes of jet fuel were shipped out of the Strait of Hormuz last year - a little over a fifth of total global seaborne exports.

The war in Iran means that supply has been cut off, and the market has since tightened further.

China - the world’s second-largest jet fuel producer - is restricting exports. South Korea, another key producer, has cut output as it struggles to source crude oil to refine.