Mariah replied: ‘No, I didn’t and normally when people ask me the ‘did you know’ type thing, I pretty much say “yeah I had an idea or I knew” but with this, I didn’t know.

‘It was the first Christmas song I’d ever written and I just wanted it to be real to me. To my little girls’ self… like, what are the things I think about Christmas, what did I want, what did I wish for?’

‘I wanted it to be timeless’: Mariah Carey, 54, wowed in a festive red dress as she revealed she never thought All I Want For Christmas would be a hit during This Morning interview on Wednesday

Insane: Since it’s release in 1994, Mariah has raked in more than $70million (£58million) for her festive classic as it continues to top the charts each year

Getting in to the festive spirit, the singer flashed her ample cleavage as she wowed in a red strapless dress for the interview.

Bringing her signature glam look, Mariah was fully dolled up and accessorised the look with a gorgeous pair of silver dangly dragonfly earrings.

She continued: ‘When I first wrote it, I wanted it to be timeless. I didn’t want it to be something that felt like a specific year – I wanted it to be something that I could have heard as a little kid growing up.

‘I don’t know what version of Rudolph The Rednosed Reindeer I heard as a kid, or Walking in a Winter Wonderland, but I just know that I loved those songs.

‘So I wasn’t thinking “oh my song is going to be as big as those songs” but I was like, “let me do something that makes me feel like I’m getting the experience of listening to a classic”.’

Most people think of Mariah as an integral part to Christmas, and as Sam mentioned her importance in the festive period the songstress smiled and said: ‘Well that’s fun to think! I love that! It feels like what you do when you set out to make music, to be a soundtrack to people’s lives.

‘It makes me happy because it’s talking about – for the most part – it’s about songs that I’ve written.

‘They are literally the soundtrack of my life, because I wrote them and a lot of people come up to me and say “hey we listen to your Christmas album in July because we don’t care what month it is!” so that’s pretty great.’

Back in the studio, Cat Deeley said, ‘I mean the minute you hear it [All I want for Christmas] you know it’s Christmas!’

Chart topping: The 54-year-old was asked by Sam Rubin whether she knew the song would become such an anthem,’No, I didn’t and normally when people ask me the ‘did you know’ type thing, I pretty much say “yeah I had an idea or I knew” but with this, I didn’t know’

Legendary: ‘A lot of people come up to me and say “hey we listen to your Christmas album in July because we don’t care what month it is!” so that’s pretty great’

‘I think it’s harder to become an established artist now’: The singer admitted it is more difficult now to break into the music industry

Christmas pay day: Last year the tune made a glittering return to the number one spot in the UK charts and continues to top up her bank account with around $3million (£2.4million) per year, the New York Post reported

Tweet: ‘I’m honored beyond belief! I definitely did not even imagine this would happen when writing and recording this song! Thank you so much Ms. Hayden and the @librarycongress,’ Carey said in her tweet

Since it’s release in 1994, Mariah has raked in more than $70million (£58million) for her festive classic as it continues to top the charts each year.

Last year it made a glittering return to the number one spot in the UK charts and continues to top up her bank account with around $3million (£2.4million) per year, the New York Post reported.

Yet while the singer has achieved worldwide success, she admitted that breaking into the music industry nowadays is more difficult.

‘I think it’s harder to become an established artist now. You could just be on YouTube and if someone finds you, you’re a star, but it doesn’t last as long. I think people have to work a lot harder to have a career in this industry now.’

Revealing what she does to keep herself in tip top condition vocally, Mariah said, ‘Rest is the best thing!’

Talking of her festive break and traditions of going to Aspen, Colorado, Mariah confessed: ‘I love having a snowy winter wonderland at Christmas, it’s the best. Afterwards I want to go somewhere warm immediately!

‘I feel like I would be missing Christmas if it wasn’t snowing.’

Back in April, the classic was added to the Library of Congress’ National Recording Registry.

The beloved song is among 25 songs added to the registry, including other hits like Madonna’s Like a Virgin, Queen Latifah’s All Hail the Queen album and Daddy Yankee’s 2004 smash hit Gasolina.

‘The National Recording Registry preserves our history through recorded sound and reflects our nation’s diverse culture,’ said Librarian of Congress Carla Hayden.

‘The national library is proud to help ensure these recordings are preserved for generations to come, and we welcome the public’s input on what songs, speeches, podcasts or recorded sounds we should preserve next. We received more than 1,100 public nominations this year for recordings to add to the registry,’ Hayden added.

Carey – who was recently spotted at the Beau is Afraid premiere – also shared the news to her millions of followers on social media, including a video where she discussed the song’s origins.

‘I’m honored beyond belief! I definitely did not even imagine this would happen when writing and recording this song! Thank you so much Ms. Hayden and the @librarycongress,’ Carey said in her tweet.