Ronan's X-tra hard challenge

Ronan Keating. Picture: Supplied

After close to five seasons as a judge on reality singing juggernaut The X Factor, Ronan Keating knows all too well about the immense pressure the show's contestants are under each week.

But having this year stepped in to mentor the under-25 girls , Keating has been faced with some difficult challenges of his own.

The 37-year-old Irish singer and heart-throb reveals that guiding WA's Sydnee Carter, 16, Queensland country sweetheart Caitlyn Shadbolt, 18, and shy NSW schoolgirl Marlisa Punzalan, 14, through their live performances each week has been the biggest hurdle he's faced since joining the judging panel in 2010.

"This has probably been the toughest challenge I've had in five years because it's the under-25 girls," Keating says backstage following a taping of The X Factor live show at Sydney's Fox Studios. "Forget about 1000 people in front of you when you're on stage, you've got two million people down the camera lens watching you.

"We give our contestants so much to think about - a mark to hit on the stage, cameras to hit, dance routines, vocals, facial expressions. There's so much that we're giving them every single week. I understand how intimidating and scary it is, I do, and I admire them all for it, the good and the bad."

Keating considers Carter, Shadbolt and Punzalan like his "daughters", which he says puts him in an even tougher position as far as the girls' on-stage outfits go.

"They're young and when it comes to the clothing I have to think about how I'm going to get around it," he says.

"With the over-25 girls, you can put them in something sexy but with the under-25 girls you've got to be careful and think about what people at home are going to think.

"I don't like kids growing up too fast, I'm the first to say 'Hang on a second, slow down'. So I kind of had that approach to my contestants. It's probably not a good thing in a way but I feel it's the right thing. And I'll stay true to that."

Although he has already copped his fair share of flak from viewers this season for his "harsh" critiques of the live performances, Keating makes no apologies for his tough- love approach.

"I'm OK with people getting offended with what I have to say," he says.

"But I have to say what I see and if I see something that is a bad song choice or a bad vocal performance, I'll say it. I won't be the most-liked person in the room. You hear the audience boo and people at home might be booing but I know the majority of people watching will be agreeing with me because I think it's naive to give a positive comment when it's not warranted, or attack someone when it's not warranted.

"People aren't stupid, people watching at home know. They make their mind up from bad and good, so I'll always stick to my guns and be honest about a performance. I believe in that. I have for five years, I always have."

He's also had his differences with fellow judges Dannii Minogue, Redfoo and Natalie Bassingthwaighte in recent weeks but insists there's no bad blood between the foursome once the cameras stop rolling.

"This is the best panel I've ever worked on," he says. "The dynamics are fantastic, the flow between us, the comments, the honesty - people say what they see and it works, it really works.

"And I really enjoy it. I love working with this team, they're a great bunch of people.

"At the same time, the four of us are all working towards the same thing. We want an incredible winner for this show and that's what we've created every year."

While there have been concerns that Australia's talent pool could soon dry up, Keating says the calibre of performers "just keeps getting better".

"I think it shows that after five years, people have seen what can happen to them if they come on The X Factor," he says.

"People don't know how good they are until they come on a show like The X Factor. And we show them how good they are, because we have the tools and the ability to make someone become a superstar.

"There's no other show in the country that can do that. If I was on a show that didn't do that, I'd be walking off. But I'm here five years later because we make stars. I'm proud of that."