Holidaymakers were today warned they face soaring air fares and cancellations this summer as ministers were drawing up plans for jet fuel shortages.

Airline bosses said soaring fuel prices sparked by the Iran war could be passed onto families looking to get away this summer if the conflict drags on.

And ministers were preparing for jet fuel supplies to ‘be constrained’, potentially threatening getaways.

‘Contingency’ plans were being drawn up in Whitehall to deal with any shortages.

A government source told the Mail: ‘The supply could be constrained, but it’s not clear how significantly yet. We are working up contingencies for if they are needed.’

The price of jet fuel in Europe soared to a record high this week, with prices almost double what they were before the conflict started.

And there are fears of shortages if Iran’s retaliatory blockade of the Strait of Hormuz continues to squeeze Western oil supplies.

Airline bosses said they bought enough jet fuel cheaply in bulk before the conflict erupted to ensure fare hikes aren’t necessary for at least a few months or so.

EasyJet boss Kenton Jarvis said there was a spike in fuel prices after Russia’s invasion of Ukraine four years ago, but that the jump caused by the US-Israel war in the Middle East has gone ‘further north’.

Asked if air fares could be higher this summer, he said: ‘The answer is yes.’

Speaking at an industry summit in Brussels, he added: ‘The longer prices are elevated, the more you’re going to have to start covering your position with more expensive fuel. So my expectation is that prices go up.

‘It’s a low-margin competitive industry. We make about £7 a seat. If fuel goes up £10, then you have to do something about that.’

Urging holidaymakers to protect themselves from fare rises, he added: ‘I think the message would be to try and book as early as possible.’

Ryanair boss Michael O’Leary said there could be ‘issues’ towards the tail end of the summer season if the conflict drags on.

He added: ‘I think it depends on how long it goes on for. If it goes on for the next month or two, which is the general expectation, then we don’t expect any disruptions.’

He added: ‘But none of us know. There’s an inevitability that if the Strait of Hormuz remains closed, that oil prices will remain elevated and it is inevitable that that will flow through to higher fares.’

The cost of jet fuel has surged more than crude oil prices partly because of Europe’s reliance on exports.

Scandinavia’s largest airline – SAS – this week became the first major carrier in Europe to scrap flights because of surging fuel prices triggered by the Iran war.

On Tuesday it said it was scaling back flights because of the ‘sharp ⁠and sudden increase’ in jet fuel costs.

Air France-KLM and SAS have already said they will have to hike ticket prices due to the rising cost of jet fuel, while Finnair has warned that jet fuel supplies may run out due to the effective closure of the Strait of Hormuz.

There are fears that more airlines across Europe and in the UK will be forced to do the same if the conflict drags on.

Speaking at the Brussels summit, former British Airways boss Willie Walsh, now chief of industry body the International Air Transport Association, said: ‘We’ve seen this before. Fuel prices will go up.

‘Higher fuel prices will lead to higher ticket prices. In terms of how high really depends on how long this lasts.’

Whether or not airlines cancel or increase fares depends on how well ‘hedged’ they are. This refers to how much fuel they bought in bulk at a certain price. Some airlines bought months’ worth of fuel before the conflict when oil prices were as cheap as $67 a barrel. But once these stocks start dwindling, airlines face having to pass on higher costs or consider cancellations.

The cost of oil has surged above $100 since the conflict broke out, with the Iranian regime threatening to push it as high as $200 by blockading the Strait of Hormuz.

Around a fifth of the world’s oil and gas passes through the Strait, meaning Iran’s blockade of it has choked off up to 10million barrels of oil a day.

Oil traders expect to see shortages of jet fuel from the continued blockade within the coming weeks as reserve supplies are run down and are not replaced.

This week, Vietnam became the first country to warn of possible flight cancellations from April after China and Thailand announced they were halting exports to maintain their own supplies.

Other countries expect to follow suit in the coming days with industry experts warning that airlines could be forced to stop serving some long-haul destinations because they may not be able to get fuel for the return journey.

The UK gets the majority of its imported jet fuel from Kuwait, Saudi Arabia and the United Arab Emirates, meaning it is also vulnerable to potential disruption if the conflict drags on.

The UK only has the domestic refining capacity to meet a third of current demand, according to the Government’s most recent security of supply report.

A Department for Transport spokesman said: ‘We are engaging with British carriers to support their operations against the backdrop of war in the Middle East, and to limit the impact on industry.’