Airlines are scrambling to redraw schedules as jet fuel shortages linked to the Iran crisis begin to bite, with one major carrier warning that some airports are already effectively dry.

Carsten Spohr, chief executive of Lufthansa, revealed that one of the airline’s long-haul passenger jets was unable to refuel after landing in Cape Town, South Africa. The aircraft was forced to fly roughly 900 miles to Namibia to take on fuel before returning to its original destination, a costly and time-consuming detour that underscores the fragility of global supply lines.

Spohr warned that carriers are now planning for a scenario in which aircraft may routinely need to make additional refuelling stops because they cannot rely on fuel being available at their intended destinations. “If you cannot reach your target airport with the fuel that you’ve got, then you have to do refuelling stops – we are not there yet, but we are preparing for this,” he said.

The disruption is already rippling through the wider travel industry. Aviation analytics firm Cirium reports that airlines worldwide have removed around two million seats from May schedules in just two weeks. Analysts fear the situation could deteriorate sharply, with up to 10 per cent of global flights at risk next month if supplies remain constrained, equivalent to about 85,000 cancellations.

Paul Charles, head of travel consultancy The PC Agency, said carriers are being forced into “difficult decisions” as they head into the peak summer season. He argued that airlines are choosing to cancel flights early rather than risk chaotic last-minute scrubs, warning that the Iran conflict is tightening the squeeze on jet fuel and could trigger many more cancellations.

Charles noted that recent changes to UK airport slot rules mean airlines can cancel more freely without losing valuable take-off and landing rights, giving them greater flexibility to trim schedules as fuel becomes harder to secure. The impact, he stressed, will vary by region and route, with some markets facing far deeper cuts than others.

Geopolitical analysts say the uncertainty is likely to weigh heavily on fans planning short trips to North America for the World Cup, even on lucrative transatlantic routes that airlines are most reluctant to cut. With fuel supplies under pressure and contingency plans being drawn up, carriers are bracing for what one expert called a “worst-case scenario” summer in the skies.