A total of 38 sailings, across a range of cabin grades, are on offer to solo travellers at no extra rate.

It includes the five-day "Amsterdam, Kinderdijk and the Dutch Bulbfields" itinerary, which starts at £979pp, and the eight-day "Douro, Porto and Salamanca" sailing which comes in at £1939pp.

Also available is the "The Blue Danube" cruise which calls at Vienna, Salzburg or Linz, Durnstein, Budapest and Bratislava, from £1519pp, and the eight-day "Rhine and Moselle" sailing, which features seven guided tours to Cologne, Koblenz, Bernkastel and Trier. Fares come in at £1969pp.

Katja Hildebrandt, from Riviera, said there had been a "noticeable increase" in guests looking to travel on a single basis since international travel started to open up.

"We’ve received clear feedback from the trade that more guests are hoping to travel as soon as possible, so we’ve added these cabins to the start of our 2022 season across a wide range of itineraries," she added.

"We’re very pleased to be able to offer solo cabins at no extra charge, as we continue to ensure our river cruises are an immersive, accessible and friendly holiday option for single travellers."