TORONTO -- Simon Cowell fully expects many TV viewers will tune in to "The X Factor" just to see if new judge Britney Spears will fail.

But he says those people will be disappointed.

Cowell says the pop star-turned-tabloid mainstay held her own throughout the show's cross-country audition tour, and would not be part of the show if she couldn't handle it.

"If that was the case we wouldn't have gone beyond one city," Cowell said during a visit to Toronto this summer to promote the new season.

"I think she would have said to me or I would have said to her: 'This isn't working. You can't cope with it or you can't do the job.' It's not the case."

Reports claiming Spears' unravelling dogged the singer early in the tour, with multiple accounts alleging she took abrupt breaks to regain her composure.

Throughout, Cowell emerged as Spears' biggest defender, and during a visit to the show's Canadian broadcaster CTV he insisted Spears is tougher than people most think.

She may even be the toughest critic on the new and improved "X Factor," he said.

"She is fearless," said Cowell, his comments coming about halfway through the tour.

"To get a 'No' out of (previous judge) Paula (Abdul) as you know was like getting blood out of a stone because she didn't want to be unpopular. Britney has literally no qualms -- she can have 4,000 people going crazy about a contestant, (and she says) 'No."'

Combined with fellow newcomer Demi Lovato, Spears is downright unshakable, says Cowell, who returns to the judges' table with producer L.A. Reid.

"When the two of them get together (and) me and L.A. want someone to go through and these two (don't), they're immovable. And that's what happens when you put two girls together."

Despite establishing himself as one of TV's harshest reality show critics on "American Idol," Cowell said he doubts he's the toughest critic out of the four judges on "The X Factor."

"Watch the tape. I'm not so sure," said Cowell, whose past barbs have reduced wannabe stars to tears and provoked expletive-laden retorts.

He said Spears is out to prove there's more to her than her rocky past and that she can be a solid judge.

"She's taken that role really seriously -- (deciding) who she thinks is a star, more importantly who isn't. And I've got to trust her instincts. And then she wants to watch the stuff back to know what she's done wrong, you know, what she can improve on, so it's not just someone taking a cheque and just turning up. There's a real commitment."

Lovato, too, has proven to be "a total brat," Cowell smirked, making no bones about the fact he added the younger crooners in a bid to court younger audiences.

"She's just completely fearless, irreverent and I think it was important because me and L.A., I'm 52, LA's a lot older than I am -- a lot -- but you know, a lot of people who watch our show, they're 16, 17, and 18 and younger. So we had to have someone, I thought, on the panel who could reflect that younger audience."

Twenty-year-old Disney queen Lovato and the 30-year-old Spears replace last season's Paula Abdul and Nicole Scherzinger.

As for ratings, Cowell said he's learned to keep predictions modest.

"I'll give you a ratings expectation: Anything over 1 million," he quipped, chastened by last year's numbers which fell far short of the 20 million viewers he predicted. "How's that? I'm not falling into that one again."

"It was a tough year last year. Once I'd opened my big mouth about the 20 million I felt, 'I'm so going to get this back.' Maybe it's karma but I learnt a big big lesson from that."

Again, there will be stiff competition around the dial this year, most notably from "The Voice" and its cast of judges Christina Aguilera, Blake Shelton, Cee Lo Green and Adam Levine.

The series airs Mondays and Tuesdays but will air a bonus episode Wednesday -- the same night "The X Factor" returns to CTV. In Canada, that special episode airs on CTV Two.

Rankled by the rivalry, Cowell couldn't help but accuse producers of "The Voice" of stealing elements from his reality series.

"You know, producers do that -- they see something they like, they'll nick it and you can end up with both shows looking the same," complained Cowell, hinting that he's got several changes in the works for "The X Factor."

"Because 'The Voice' is on a similar time to us, we have to look as different as we possibly can, not just from them but from what I made last year as well, and from what we saw on 'Idol' this year. It has to have it's own DNA and it's own characteristics."

Cowell also said he's bored with "American Idol," a one-time ratings juggernaut that is also retooling its judging panel before returning early next year. So far, that includes adding diva Mariah Carey, and a new role for longtime judge Randy Jackson.

Cowell called his stint there "like being on 'Groundhog Day."'

"It's 10 years old. I mean, that's why I left, it's like dating someone for 10 years. After five years it's kind of like, we're reaching that point of kind of getting fed up with each other. After 10 years, bye!"

"The X Factor" returns with a two-day premiere Wednesday on CTV and continues Thursday on CTV Two.