Demand this year is also particularly strong for smaller European destinations including Cyprus, Bulgaria, Croatia and Portugal, Cook said.

For the summer, in the UK, amid “a more competitive market to the Spanish Islands”, Cook said its focus remained on selling “higher margin, quality holidays rather than pursuing volume growth”.

As a result, charter risk pricing was up 9%, while bookings were slightly behind last year.

For the UK as a whole, including seat-only and non-risk package holidays, bookings were flat overall and average selling prices up 3%.

The UK business has further expanded its winter sun programme with bookings up 6%, “reflecting strong growth in both charter risk package and seat-only sales”, with pricing down 1%.

In continental Europe, pricing was up by 2% while bookings were 2% lower, reflecting weaker demand for Turkey than last year.

For northern Europe, bookings were slightly below last year’s “exceptionally strong levels”, and pricing down 3%.

Cook said trading for the group was progressing in line with its expectations.

It said while it is seeing some margin pressure in parts of the business due to more competition, overall demand for summer holidays was strong.

“Based on our current trading performance, and supported by further financial benefits from implementing our strategy, we continue to expect our full year underlying operating result to be in line with current market expectations,” the company said in a statement.

Peter Fankhauser, chief executive of Thomas Cook, added: “Customers’ appetite to go abroad on holiday this summer is good across all our markets despite continued political and economic uncertainty.

“Our decision to expand our holiday offering to Greece has helped support customer demand, with bookings to Greece up by around 40% versus last year, while smaller destinations like Cyprus, Bulgaria and Croatia are also proving popular.

“After a slow start to the season and a tough year in 2016, we’re seeing early signs that customers are beginning to go back to Turkey and Egypt.

“Following strong growth last year, bookings to the Spanish Islands have levelled off in a very competitive market. Competition is particularly intense in the airline sector, putting downward pressure on pricing.

"As we look ahead to the rest of the year, I am confident that the work we’re doing to strengthen the quality and appeal of our holiday offering will win more fans for Thomas Cook, demonstrating continued progress in our transformation to put our customers at the heart of the business."