A marriage proposal, strange similes and a stunning panorama marked the public opening of the viewing deck for western Europe's tallest tower on a wet Friday in London.

The Shard skyscraper was described as an "intergalactic spear" and a "cocktail stick" by Mayor Boris Johnson, who cut the ribbon for the first public visitors atop the 310-metre tower. One visitor proposed to his girlfriend of five years. James Episcopou, 22, said: "She makes me feel like I'm on top of the world so I thought the highest place in London has got to be the best place to do it."

His fiancee, Laura Taylor, 22, said: "I just feel overwhelmed, surprised and the view is fantastic."

The Shard is majority owned by Qatar and houses a hotel, restaurants, 12 floors of apartments, office space and the viewing deck.