Marketing director Christopher Edgington said pre-registrations, targeted at past passengers only, allowed clients to put their name down for specific cruises but not cabins.

The maiden voyage, a 14-night Mediterranean cruise departing March 14 2015, was in high demand, as was a 12-night round-Britain cruise in July. They open for sale on March 27.

Speaking at Britannia’s float out – the moment when the dry-dock is flooded and water hits the hull for the first time – Edgington said: “Our past passengers are really excited about Britannia. We have created a ship that is right for them and for people who have never cruised by enhancing our signature features and adding exciting new ones.”

They include a new cookery school devised by TV chef James Martin, the Limelight dining and cabaret club, and a Mediterranean-style Market Café serving charcuterie and sweet treats from TV’s Cake Boy Eric Lanlard.

Michelin-starred chef Atul Kochhar and wine expert Olly Smith, who have venues on other P&O ships, are also part of Britannia’s culinary line-up. Instead of a restaurant, Marco Pierre White is creating dishes for gala nights in the dining rooms,

Hebden Bridge-based agent Louise Hunt, who works for Travel Councillors, won a P&O competition to be Madrina, or godmother, for the float out, at the Fincantieri shipyard in Monfalcone, Italy. A bank worker until last year, Hunt admitted she was both nervous and excited. She said: “This is quite surreal, quite incredible.”