Britney Spears is ‘mean’, Simon Cowell has joked.

The new US X factor judge attended a press conference with Simon to mark the start of the boot camp round of the show when he made the remark.

Simon laughed that 30-year-old Britney’s judging style is tough and brutal while answering questions about the show in Miami.

‘Britney’s quite mean, as you’ll discover,’ he joked. ‘She’s as sweet as a lemon.’

Simon went on to heap praise on the singer. The media mogul admitted that although Britney is a tough cookie, she is a very talented mentor.

‘I was fascinated with her as a person, as a pop star, and there’s something intriguing about her,’ he continued. ‘And she’s a really good judge.’

Britney added: ‘We just all met up and it made sense. I adore Simon and it was something I really wanted to do.’

Joining Britney on the panel of the programme is 19-year-old Demi Lovato and veteran panel member LA Reid. Demi is adamant she brings a lot to the show despite her tender years.

‘I think that the expertise that I’m able to contribute is I’m listening to the radio right now and I know a lot of what my friends like, and we’re in our early 20s and late teens,’ she explained.

‘I think we know what is needed in this industry and what is missing.’       –MSN