Britain's Duchess of Cambridge Kate Middleton christened a gigantic new cruise ship named Royal Princess by smashing a bottle of champagne against its bow.

The ceremony organised by the cruise liner's owners, Princess Cruises, took place in Southampton, UK and represents Kate's last solo duty before giving birth to the next heir to the throne.

The predecessor to the new Royal Princess was christened by Diana, Princess of Wales in 1984.

"I name this ship Royal Princess. May god bless her and all who sail in her," said the Duchess, prior to cutting a string and inaugurating the liner by smashing a 15-litre bottle champagne against the bow.

The duchess was under scrutiny for any hints about her baby when she launched the new 3,600-passenger vessel on England's south coast. Wearing a small, black hat and black-and-white dalmatian print coat, the duchess was careful to give nothing away. In March, a slip of the tongue sent public speculation over the sex of her baby into overdrive, when she accepted a gift from a well-wisher saying: "Thank you, I'll take this for my d.."

Following the slip bookmakers William Hill have said this erroneous "d" had led to such wide speculation that the baby was a girl that it suspended all gender bets a few weeks later.

Bets on names however have continued to roll in with Alexandra the favourite at William Hill. The second favourites are Diana, after Prince William's mother who died in a car crash in 1997, and Elizabeth after the current monarch.