Ant and Dec have admitted they thought their careers were going to be ended by the 2007 phone voting scandal.
The Geordie TV duo, appearing together on Desert Island Discs, also defended the treatment of Susan Boyle on Britain's Got Talent, which they host.
ITV was fined more than £5 million by communications watchdog Ofcom after it emerged that viewers on shows including Saturday Night Takeaway had paid to enter premium rate phone competitions which they stood little or no chance of winning.
Ant told host Kirsty Young the scandal was "the worst part of our career", adding: "I think our audience trust us and with that case we were really worried that trust had gone."
Dec, who said the pair "couldn't quite comprehend how it was allowed to happen", said he thought their career was over.
He said: "We thought that probably that was it, to be honest with you, because I think the viewers would have been justified in thinking their trust had been breached, and if that had been the end, I don't think we could have had many complaints."
The stars - real names Anthony McPartlin and Declan Donnelly - chose two tracks each and four songs together on the BBC Radio 4 show.
They are the first duo to appear on the historic programme since Spitting Image creators Peter Fluck and Roger Law in 1987.
Speaking about the rumour that he once considered joining the priesthood, Dec said there was the "tiniest seed of truth in it".
The presenter, whose older brother is a priest, said: "I thought about it and then got the bus home and saw all the girls from local convent school, Sacred Heart, passing by and I thought it's not for me."
Defending Britain's Got Talent from what Young called "considerable and consistent criticism" of how Boyle was treated, Ant said: "We worried about her a lot and the duty of care that they have on Britain's Got Talent for the contestants is very high - there's somebody constantly there for them - but she found it hard just being in London, being away from Scotland and so on...
"You're not even putting into the mix global fame and YouTube hits and all that kind of stuff, so she did find it tough and, you know what, most people would."
The pair, whose song choices include Bring Me Sunshine by Morecambe and Wise and the theme to 1980s drama Auf Wiedersehen, Pet, also said they still wanted to star in a sitcom together.