We told yesterday how the BBC One series had overtaken the ITV1 show on Saturday night, with an average audience of 9.5 million viewers.
And almost four million viewers opted for The Voice in favour of BGT when the two shows clashed for two minutes from 8PM.
“Simon wasn’t happy when he saw the ratings. He likes to be number one in everything he does. He has told producers they must make BGT even better," an insider told The Sun today. “He is known as being a perfectionist and this will only renew his desire to beat The Voice.”
The insider claimed that the ratings weren't just worrying for BGT, but also for their sisters show The X Factor, which returns in the summer.
“The big fear is that viewers will start seeing The Voice as the leading singing show," the source explained. “That would mean the best singers flocking to apply to it instead of The X Factor — and these shows live or die on their talent.
“Simon always learns lessons. He will be seriously considering whether he has to be nicer to contestants.
“He has softened his Mr Nasty image over the years. But maybe now he needs to turn fully into Mr Nice. It’s clear viewers are starting to get a taste for more positive shows.”
A spokesperson for Simon last night insisted: “Simon is happy with the ratings. The judges are looking forward to the live shows.”
Meanwhile a BBC source took the opportunity to stick the boot in to the music mogul.
"These figures show we made the right choice bringing The Voice to BBC1," the insider told the Daily Mirror. "People are excited by our format and tired of Cowell’s gimmicks.”
Both shows continue this Saturday.