Rod Stewart replaced Tom Jones at the Queen's Platinum Jubilee concert earlier this year after a massive behind the scenes bust up between the 'Sexbomb' hitmaker and Dame Shirley Bassey.
Sir Tom, 82, says everything fell through after Dame Shirley refused to do a duet with him, because she wanted her own sparkling slot on stage.
Everything is reported to have been up in the air, leaving a lot of uncertainty as to how things would work, so Sir Rod stepped up and offered his assistance, reports the Mirror.
"I thought it was a good idea. She would be the surprise guest and I would've said, 'Here is Dame Shirley Bassey to help me with the next song', said Tom.
"Then I would do mine and then we would do a duet. Which is fair enough but if she could not do that then she did not want to do it."
In the end, neither singer performed. Sir Tom said that was also down to him being asked to "run up and down a ramp" while singing Sweet Caroline because he is awaiting a hip replacement.
He added: " Rod Stewart ended up doing it. It was all very much up in the air so Rod said, 'I will do it'."
Sir Tom will be back on our screens as The Voice UK returns to ITV on Saturday.
He said he had postponed his hip surgery until October 28 so he could finish his US tour Surrounded by Time and not upset fans.
Sir Tom said: "I have got to have a new hip. I had this one done [left] five years ago and it works great, so now this one is starting to go." He does not take painkillers but now has a walking stick.
Sir Tom added: "I am all right for four songs and then it starts to hurt and I sit on a stool. I am as dedicated as the Queen. I have got to be steadfast."
The Voice UK will go head-to-head with Strictly Come Dancing on BBC1 later this month.
Don't miss the latest news from around Scotland and beyond - Sign up to our daily newsletter here .
READ NEXT
