Britney Spears with L.A., Demi and Simon

The US X Factor 2012 is underway with two new judges, both Demi Lovato and Britney Spears made their debut this week on the Fox reality TV singing competition.

While Demi did just fine, Britney really seem to stand out with some of her comments played on the show and aimed at the would be contestants at the auditions.

In fact, Britney has been dubbed the ''fearless'' judge on US 'X Factor', according to Simon Cowell.

The pop star joined the panel of the show for its second season alongside fellow newcomer Demi and original judges Simon and L.A. Reid and Simon was hugely impressed with the 'Toxic' singer.

He said: ''She's fearless. When she says 'no' or disagrees, she couldn't care less.

''I think she's really enjoying doing something other than singing. I think she likes being part of a team.''

However, he admitted it wasn't smooth sailing from the start, explaining: ''The first day, the second she said 'no,' everyone booed her and that happened a lot and I think she found it very intimidating.''

Yet Britney thinks Demi is even tougher than her, calling the 20-year-old judge a ''spitfire''.

She said: ''I think Demi [is tougher], I just do. She's a little younger than me so she's a spitfire.''

Meanwhile, Demi admitted she and Britney, 30, struggled at the start of the competition.

She told People: ''We got more comfortable in telling our opinions without being afraid of the booing. When Britney and I first started on this show, we were looking at each other like, ''What do we do? We're so nervous!'''

© Bang Showbiz