"I had an email conversation with the BBC about it but it just didn't feel right," he confirmed to the Daily Star. ''The reason to say yes to the offer is obvious - those huge viewing figures would have shifted us a lot of records.
"The musical landscape has changed a lot since our first single in 2004, and the way of the world now is if you're on one of those big TV shows, you sell records.
"But if you've got that one bit of doubt, you should listen to that more than the 99% of you that's screaming, 'Do it'."
Jessie J, will.i.am, Sir Tom Jones and Danny O'Donoghue coach The Voice UK, which launched on BBC One last month.