Ryanair is no longer Europe's largest airline after a rostering issue in 2017 saw thousands of flights cancelled and a number of routes suspended throughout the continent.

In September 2017, the airline cancelled numerous flights in what was called an error “in the planning of pilot holidays”, though its slip to second place in the list of Europe's largest airlines was also influenced by Lufthansa's acquisition of Air Berlin.

The German airline had 9.3 million passengers in December 2017 alone. In a statement provided to The Independent, it said: “In 2017, Lufthansa German Airlines carried 66.2 million passengers, 6.1 per cent more than in the previous year,” while Lufthansa Group - which includes Lufthansa, Austria, Swiss and Eurowings - carried "130 million passengers" in total.

In 2016, Ryanair was Europe's biggest airline with 116.8m passengers, followed by the Lufthansa Group at 100.7m. IAG (British Airways, Iberia, Vueling and Aer Lingus) came third with 100.7m.

Speaking to The Independent about the change, a Ryanair spokesman said: “This is expected given that Lufthansa is growing by acquisition whereas Ryanair continues to grow organically. Next year, as we grow to 140m passengers, we expect to overtake Lufthansa again, unless they acquire some other airline to boost their figures.”

He also noted that “Ryanair’s 2017 annual traffic grew by 10 per cent from 117m to 129m customers.”

In December of last year, Ryanair announced that it would begin recognising pilot unions in order to avoid Christmas strikes like those witnesses in the autumn. The airline's chief executive Michael O'Leary said: “Christmas flights are very important to our customers and we wish to remove any worry or concern that they may be disrupted by pilot industrial action next week.”