The operator made a pre-tax loss of £64 million for the three months to the end of June, compared to a loss of £44 million in the same period in 2015, as revenue slipped from £1.95 billion to £1.85 billion year-on-year.

Overall booking levels for summer 2016 fell by 5% for the operator due to “weak demand” for Turkey, despite strong growth to Spain – particularly the Canaries and the Balearics which have seen rises in sales of 18% and 11% respectively.

UK bookings for this summer are currently down by 1%, compared to this time last year, while average selling price is also down by 4% - mainly due to a drop in seat-only prices. Although prices for package holidays have risen by 2% over the same period.

Cook reduced its profit forecast for the current financial year to around £300 million – the company had said in May that it expected to make a profit of between £310 million and £335 million.

The UK business made an underlying profit before tax and interest of £34 million during the last quarter – down by £3 million year-on-year – due to “shoulder season weakness resulting in lower load factors”.

Chief executive Peter Fankhauser said: “Our financial result in the third quarter was in line with our expectations when we last reported in May, following the impact of the attack on Brussels airport in March and continued weak customer demand for Turkey.

“Since the half year, we’ve taken action to further reduce our capacity to Turkey and increased sales of holidays to other areas, including the Western Mediterranean and long-haul destinations such as the USA.  Growth to smaller destinations such as Bulgaria and Cuba is also strong.

“We are operating in a challenging geopolitical environment, with repeated disruption in some of our key source and destination markets.  In addition, while Brexit has had no noticeable impact on our bookings so far, it has added to a general sense of uncertainty - for our business and our customers alike.”