Pop superstars Rihanna and Justin Bieber are taking over the main stages at V Festival this weekend.

Taking place across two sites, Justin will make his V Festival debut at Hylands Park in Chelmsford, Essex, on Saturday, alongside acts including Sia, Bastille, Jess Glynne and Stormzy, before moving to Weston Park, Staffordshire, on Sunday.

Justin Bieber has demanded 800 gallons of water for his set (Chris Pizzello/AP)

The Love Yourself singer will swap with Rihanna, who shares the main stage with David Guetta, Little Mix and Years & Years in Staffordshire first, before closing the festival in Chelmsford on Sunday night.

Justin is planning to make a splash with his set. He has requested 800 gallons of purified water at exactly 40C as part of a huge spectacle happening during his show.

Rihanna will get Staffordshire dancing first (Rich Fury/AP/PA)

The festival said the production is one of the most challenging in its 21-year history.

Other acts among the line-up include the group Faithless, American singer Halsey, garage star Craig David, rapper Tinie Tempah and British rockers Kaiser Chiefs.

V Festival will take place at Hylands Park and Weston Park over the weekend of August 19 to 21.