TUI, Europe's largest package holiday operator, has warned that between 10% and 25% of its jet fuel supplies could be at risk through May and June if the Middle East conflict continues. The company told Belfast Live: "We think there is a reasonable risk, some low level, maybe 10% to 25% of our supplies might be at risk through May and June, so like everyone else in this industry, we hope the war ends sooner rather than later."

Ryanair has added to the warnings, stating that the continent may have only six weeks of airline fuel remaining. One industry assessment noted that if the U.S.-Iran conflict ends before April does, May and June flights will not be affected. April ends within days of the warning.

For European hoteliers the exposure is structural. Europe imports most of its airline fuel, so a supply pinch would bite harder there than in North America. Airlines cannot raise fares on tickets already sold, but they can cancel flights outright — a monetary calculation, since cancellations also cost carriers money.

Which flights actually get cut?

Consumer magazine Which? pushed back on the panic narrative in an April 22 article, arguing that "airlines are choosing to cancel some flights to protect profits, not because they have run out of fuel." Which? added that it does not expect widespread flight disruption this summer — "unless the situation significantly worsens."

For operators, that caveat matters. A cancelled flight still ruins an individual holiday even if the systemic picture remains calm, and island destinations carry the highest risk because air travel is the only fast way to reach them.

TUI faces particular exposure because its planes funnel guests directly into its own hotels. Operators with integrated aviation and accommodation models will feel any flight cuts first and hardest.

What does the EU plan do?

Also on April 22, the European Union released a plan named AccelerateEU, setting out four actions:

• Establish an EU Fuel Observatory to map jet fuel supply and available stocks across the bloc
• Coordinate immediately with member states, fuel suppliers, airlines and airports on alternative jet fuel sources and propose optimized distribution across all regions and airports
• Clarify existing flexibilities under EU legislation on anti-tankering rules and the use of other imported fuels to address potential shortages
• Assess whether EU rules on strategic stocks need to include specific jet fuel requirements

Anti-tankering rules currently prevent aircraft from carrying excess, heavy fuel from cheaper non-EU locations to avoid paying for expensive sustainable aviation fuel in Europe — a mechanism designed to lower emissions that may now be relaxed to ease shortages.

The United Kingdom, outside the EU since Brexit, sits beyond the scope of AccelerateEU and must manage any shortage through its own arrangements.

New border-entry procedures, whether attributed to Brexit or Europe-wide immigration concerns, add a further layer of friction for arriving guests this summer.

Hoteliers should now watch two markers: whether the conflict subsides before the end of April, which would spare May and June schedules, and how quickly the EU Fuel Observatory translates into concrete distribution decisions. A prolonged escalation would put island and package-dependent markets first in line for a summer of cancelled arrivals and empty rooms.