THE world's biggest cruise ship is "like a construction site" and poses numerous safety risks, according to some of its first paying customers.

Overflowing urinals and shattered glass are among the complaints lodged by angry passengers on Harmony of the Seas.

Operator Royal Caribbean said "finishing touches" were being made to the $1bn (£784m) ship, which first left Southampton last week.

Other complaints included broken toilets, late-night construction work and a lack of baby food despite charging £140 a night for a nine-month-old.

Passenger Christopher Hudson said: "It is like a construction site. People shouldn't be paying to be on there yet - it felt like there were as many site workers as paying guests on board."

Frequent cruise-goer Jonathan Hardy said the ship was a "shambles" and up to 100 people were regularly seen queuing to complain.

"The ship would be fantastic if it was completed, but it was a health and safety risk," he said. "That ship should not have sailed with passengers on it."

He added: "We were led to believe it was the first maiden voyage - we could buy items on board that said 'inaugural cruise'.

Some passengers have claimed staff on board wanted to offer refunds but were overruled by head office.

Others posted videos and photos online of construction work continuing until as late as 10.30pm.

Describing the cruise as a "pre-inaugural sailing", a Royal Caribbean spokesman said: "Whilst the ship is cleared for operations and many of its features are already being enjoyed by thousands of guests, as with any new build, we are still finalising some finishing touches, and thank guests for their patience as we complete these.

"As always, Royal Caribbean's highest priority is to ensure the safety of all its guests and crew members and any final maintenance is being carried out in accordance with strict safety guidelines. These early sailings were made possible due to the early delivery of the ship and we hope this has been reflected in the great value offering guests secured for their holiday."

Around 6,000 passengers joined the ship's first outing. Royal Caribbean says the official maiden voyage will sail from Southampton to its summer base of Barcelona on Sunday.