The event, which features Scissor Sisters, will also be shown on TV

DJs Chris Moyles and Jo Whiley will introduce Razorlight, Mika, Kasabian, The Fratellis and Natasha Bedingfield.

There will be 30,000 free tickets to the event at Moor Park, Preston, on 19 and 20 May.

Registration is open until 2000 BST on 7 May, with the majority of tickets going to those living near the venue.

Intimate event

The event will have a main stage, a new music stage and an outdoor arena.

Kaiser Chief's Ricky Wilson said: "The Kaiser Chiefs are pretty much delighted to be playing Radio 1's Big Weekend.

"We did it a couple of years ago and no-one really knew who we were, so it will be nice to come back as megastars."

Jo Whiley added: "This is what kicks off the festival season for me.

"It's always a lot of fun and a brilliant chance to see a stack of bands in just two days - because it's so intimate you don't have to do the legwork like at Glasto and other festivals."

The Big Weekend will be broadcast on Radio 1 and be available to watch on BBC Three, BBC Two, on interactive TV and online via the Radio 1 site.