Simon Cowell was worried his US 'X Factor' show would be over after its second episode.

The music mogul - who spent £100 million launching the American version of the pop star search show - was "tense" about the ratings and feared it could be the end of the project if it lost a significant number of its 12.4 million viewers from the opening night.

And in fact somebody said to me, 'If this drops off 30 per cent Simon, it's probably going to be all over.' That is when I was tense.

Simon - who previously said viewing figures of less than 20 million for the series would be a failure - said: "I wasn't opening any champagne on the first day because now we had set everyone's expectations.

"The worse thing was in the second day because if you have a 30 or 40 per cent drop off, you're dead.

"And in fact somebody said to me, 'If this drops off 30 per cent Simon, it's probably going to be all over.' That is when I was tense."

The 52-year-old star accepts there are a "ton of people" who didn't want him to succeed on the show - which averaged 12 million viewers after its first two episodes were broadcast Stateside - but he is confident the ratings will increase.

Speaking to the Daily Star newspaper, Simon - who quit the UK 'X Factor' earlier this year to concentrate on the new version - added: "As much as people want you to succeed, there's a ton of people that want you to fail and I took a bit in the neck that first day.

"But I always trust the public and I get a feel for the show and it's been positive and starting to grow now."