Britney Spears planning 'surprises' for Las Vegas shows

Britney Spears has urged fans who have enjoyed her Las Vegas show to come back for more as she's planning to revamp the stage spectacular.

The Toxic singer kicked off her residency at the Planet Hollywood resort in December 2013, and her shows are still selling out, prompting Britney to extend her run in Sin City and rework the show, so returning fans see something different.

"There's a lot of surprises," she told news show Extra. "There's a lot of new costume changes. There's a lot of new surprise songs in there from artists I really respect. There's a lot of prop changes and there's more to come this year that's gonna be changed."

And there will be new music too, once the pop superstar has released her ninth album: "I have a new album coming out soon, so it's just like a taste of what's to come. The new stuff isn't actually in it (show) yet."

Some of the songs Britney has been performing as part of the Piece of Me shows will be dumped, as will the star's occasional rants from the stage - in August (15) she hit the headlines when she was caught on camera telling fans, "Frankly, men can suck my f**king toe."

She's laughing about the outburst now, explaining, "(I had) men issues and daddy issues. I'm behind that now."

Britney hopes the celebrities who have checked out her Vegas shows keep coming, but she'd rather not know they're in the audience: "It makes me nervous. I really look up to those people."

Meanwhile, the stars who have tasted a Piece of Me include Miley Cyrus, Katy Perry, and Selena Gomez, and Adele has hinted she might be checking Britney put this year, which has put the pop singer on alert.

"I love her she's great," Britney added. "She's the f**king queen!"