The pair of vertically integrated listed tour operators – along with the likes of easyJet and Monarch – are both struggling to return stranded British holidaymakers after the suspected bomb attack on Russian Metrojet flight 9268.

All UK airlines have suspended services to the resort until at least November 25 and are currently working on rescue flights.

A statement at the weekend by a government spokesperson suggested that tour operators and airlines would foot the bill for any extra costs incurred because of the prolonged stay.

Operators that choose to shake up their winter programme and replace Sharm with other destinations are also likely to take a significant hit.

Analyst Mark Brumby at Langton Capital said the cost to the big two could hit seven figures.

“If you’re a hotel in Sharm you’ve got a lot of serious problems. But if you’ve got to reschedule from Egypt to the Canaries then you’ve got an issue that is solvable; you know what the answer is… put on different capacity,” he said. “[But] the rescheduling is bound to cost money.

“And sending planes over there and having them turned around and then having to send them again to repatriate people is [also] not helpful.

“I would have thought it’s going to cost millions. It should be less than Tunisia – the destination is relatively less important but it’s got to be seven digits I would imagine.”

Others in the City agreed that the impact would also be less financially damaging – at least for Thomas Cook – than June’s terrorist attack in Tunisia. “We would not expect the suspension of flights to Sharm el Sheikh to have a material impact on [Thomas Cook] group profits, as this is the low season for Egypt, and it seems like a temporary issue,” analysts at Morgan Stanley said on Friday.

“TCG’s volumes in Egypt are also only 10% of what they were in Tunisia during its terrorist incident [which cost the group £20 million in 2015].

“If holiday demand for Egypt is very weak in 2016... this would likely cause more guests to switch to markets like Spain where tour operators’ margins are lower.”

Shares in Thomas Cook and Tui both dipped – by 8.4% and 2% respectively – in the wake of the government’s decision to suspend flights last Wednesday.

Although the UK Foreign Office has not changed its advice on Sharm el Sheikh it is advising against “all but essential” travel to and from the resort.

Andy Cooper, an independent travel consultant and former director of government and external affairs at Thomas Cook, said: “It’s difficult to judge how long the problem will last because it depends on how quickly government concerns about security can be addressed.”

He added that if the issues at the airport could be solved then the market could be reopened.

“If they can fix that suitably then there’s no reason the programme shouldn’t recover and start operating again normally, which is why I suspect no one is taking a long-term decision about taking it off sale,” he added.