Sir Tom Jones has been a mentor on The Voice UK for 12 seasons, including during its initial BBC run.

Sir Tom Jones once savagely described one of his co-stars on The Voice UK as an “unknown” celebrity. The iconic singer favourably wrote about will.i.am and songwriter Jessie J in his 2016 memoir but seemingly didn’t extend the same grace to fellow mentor Danny O’Donoghue.

The Voice UK stalwart Tom, 84, has been a firm fixture on the talent competition since it began airing in 2012. The ‘Sexbomb’ hitmaker has served as a judge on every season of the show except its fifth instalment when he was temporarily replaced by Paloma Faith.

Ahead of the 2012 premiere of The Voice UK on BBC, Tom became acquainted with his fellow coaches for the first time on a press tour. These were singer-songwriter Jessie J, 36, The Script’s Danny, 44, and will.i.am, 49.

Writing about the meeting in his autobiography Over the Top and Back, the musician stated it took place in a London hotel. “There’s a press launch for the first series at a hotel in London. Will and Jessie are huge pop stars at this point,” he penned.

“Danny’s the unknown Irish guy. And me…well, I’m Nelson’s Column, or something. A monument of some kind. I haven’t quite worked it out yet.”

After describing ‘Domino’ favourite Jessie as a “talented” and “ballsy kid”, he went on to praise Black Eyed Peas’ will.i.am for being “bright” and “out there” with a “producer’s approach”.

However, Tom’s comments regarding Danny were not made in a similar vein.

He said: “And then there’s Danny who, because he has the lowest profile of the four of us, will have to put up with being called ‘Danny I Dunno Who’ when the series kicks off.”

However, it wasn’t all bad, as the Welsh icon added: “But he’s smart and funny and properly knowledgeable about music.”

Tom and Danny worked together for two seasons of The Voice UK before the Irish musician was replaced by Kaiser Chiefs frontman Ricky Wilson.

Following his exit from the programme, the Dublin-born star later admitted he left due to his mother falling sick

“I enjoyed my time as a judge and mentor and I think the misconception is that I got annoyed with it,” he told the Daily Mail.

“But when mum had the aneurysm I had to retreat from the public eye because I knew I couldn’t be a family man, look after The Script and be on a show as demanding as The Voice as well.”

Earlier this year, the ‘Breakeven’ hitmaker revealed he and Tom enjoyed a six-hour champagne-drinking session during their Voice UK heyday.

Appearing on BBC Radio Wales, Danny said: “It was after one show on The Voice and we were in the Lowry [hotel] up in Manchester and we went drinking that night, and he was telling me all these stories about Elvis and the Rat Pack and every time the champagne got to like a certain level, he’d be clicking [his fingers] to get another bottle of champagne.

“And he said you can’t leave the table until the champagne is done. And it just wouldn’t stop. We’re probably there six hours or something from 12 o’clock to six in the morning.”

Danny added that the following day he checked himself into a hospital where practitioners stated he’d begun suffering atrial fibrillation (AFib).

As per the NHS, AFib is a heart condition that can cause an irregular or abnormally fast heart rate.

Problems that can arise include dizziness, shortness of breath and exhaustion.

Danny explained that his AFib diagnosis caused him to miss “one or two days of filming” for the former BBC show and that he “should have stopped drinking” earlier in the evening.