The X Factor judge Tulisa Contostavlos has predicted that series winners Little Mix will be bigger than her own band N-Dubz – and could even be as successful as the Spice Girls.

Tulisa – who mentored the girlband to victory on this year’s series – told the Sunday Mirror they were coming into the market at just the right time.

“The girls are going to be the biggest girl band we’ve had for years. They’re coming into the ­industry when there’s a big gap in the market for them,” she said.

“There’s a lot of ­pressure on them to deliver but they can do it. People are ­saying they could be as big as the Spice Girls and I really think they could. They want to work their butts off and they’re so focused.”

Tulisa added that their debut single Cannonball was “just a formality”, saying that she couldn’t wait for them to begin recording their own songs.

“The real fun will begin when they get in the studio and find their identity,” she said. “That’s when they’re going to start the ball rolling.”

The N-Dubz singer also revealed that she was keen to return to the show next year but had yet to hear anything official.

She admitted she had had to work hard to prove herself to the show’s audience – and as such was thrilled to have the chance to perform with Little Mix in the final.

“I felt like I had to justify why I was there in a way – even during the ­final,” she told the paper. “So actually being able to sing live with the girls in the final was a massive deal for me as well as them.

“People finally got to see that I wasn’t just some street rat girl from N-Dubz who didn’t have any talent. I got to show them what I was made of.”