Prime Minister John Key and family posed backstage with pop superstar Katy Perry after her sold-out show at the Vector Arena last night.

But the 30-year-old sequined pop starlet was almost outshone in the fashion stakes by Key's flame-haired daughter Stephie, who stood out in an eye-catching pink singlet and pants outfit.

Mum Bronagh was dressed more conservatively in a striped blouse and black trouser combination.

Posting on his official Twitter account, Key wrote: "Awesome show, @KatyPerry. Thank you for giving us the chance to say hi with Bronagh and Stephie."

Perry kicked off the New Zealand leg of her Prismatic World Tour in Auckland on Friday night.