Speaking on board the line’s newest ship Symphony of the Seas during a Facebook Live with TTG, Ben Bouldin said the 0.5% figure released by Clia this month, which followed a 5.6% rise for 2016 and 8.8% in 2015, was “not as exciting as we would like”.

However he predicted that having the 6,680-passenger Symphony of the Seas - now the world’s largest cruise ship - homeporting in Barcelona this summer would help boost figures for 2018, insisting that the ship would be “heavily sourced by UK and Ireland guests”.

“We had a Freedom-class ship last year so we have a much bigger capacity. We will be sourcing more of that and we will be growing again. Those are not small step changes and that is a lot of capacity,” he said.

Bouldin described how the increase in staterooms added to the renovated Independence of the Seas, due to relaunch in May, would also boost UK passenger numbers.

“The capacity of that ship has gone up and over the full season that is a marked difference,” Bouldin added.

He was joined in the discussion by Simone Clark, senior vice-president of global supply at Iglu and Miles Morgan founder of Miles Morgan Travel. Morgan agreed with Bouldin, stating that he was "surprised to see the Clia results because that’s nowhere near a reflection on our performance".

“Certainly for 2017 and again for this year cruise has easily outperformed everything by a long, long way and it’s been the star turn by a mile. Why is that? I think as there are more ships in the market and it becomes a more complex sale and people need advice and expertise on that.”

Meanwhile Clark said she believed previous year’s passenger statistics had been “artificially high” due to “a lot of really late cheap capacity” in the Mediterranean as Americans avoided Europe due to a series of major terror attacks across 2015 and 2016.

She reported that Iglu was “really positive” for 2018 and had already seen bookings coming in for 2019 and 2020.

“We are finding that people are booking further out and spending more, and as they cruise more often, they are starting to really know exactly what they want, what cabin to book – and they are going in at the higher grade of cabin a lot of the time,” Clark added.