The cocktail bar you can’t leave

Orange uniforms and sadistic guards might not sound like the ideal ingredients for a fun night out, but Alcotraz cocktail bar believes London’s drinkers are ready for some time in the cooler.

“Back against the wall!” a guard barks to a group of thirtysomethings celebrating a birthday.

The guests comply, slipping into orange jumpsuits with numbers sewn on.

For the next two hours, they will be harassed by staff from Alcotraz, a pun on the name of the famous San Francisco prison.

The concept is the idea of 27-year-old entrepreneur Sam Shearman.

Said David Morgan, 32, a finance worker: “You need to experience this once in your life.

“It’s something that you need to put on your bucket list.”