How Adele lost £2m - and her celeb pals - on her big comeback: Singer enlisted help of Phil Collins and Damon Albarn to write new album... but scrapped songs when they 'weren't good enough' 

She has admitted that her latest album – the first for four years – very nearly didn’t happen because her newfound happiness caused her to write ‘boring’ songs.

But as Adele saw her hotly anticipated new single from the album topping the charts on both sides of the Atlantic, the true cost of her comeback in cash and reputation began to emerge.

Music industry sources told The Mail on Sunday that Adele’s inability to write new trademark songs of pain and heartache meant the new album, 25, has cost as much as £4 million to make, with at least half of that wasted on material which didn’t make the final cut.

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Adele, pictured, wasted as much as £2million on her latest album scrapping songs which did not make the cut

According to music industry insiders, since Adele, pictured, got happy, she could no longer write songs

Phil Collins, pictured, wrote a song for Adele's new album, but it did not make it onto the final record 

Damon Albarn collaborated with Adele on the album. He described some of the tracks as 'middle of the road'

She has also alienated some of the biggest names in music who collaborated with her only to be left furious when she tossed their work aside.

‘The average cost of an album by a star of her stature is around £2 million ,’ one music executive said. ‘This new album hasn’t just been blood, sweat and tears. It has been millions of pounds down various drains, deadlines missed and record company executives tearing their hair out wondering if anything was ever going to be finished.’

It is understood that the £4 million bill includes the cost of compiling an entire album’s worth of music on the theme of motherhood – a project that was scrapped even though the record company had reached the stage of commissioning art work.

As Adele embarked on a publicity blitz to promote her new song on Friday, she admitted: ‘I wrote a lot of songs that didn’t make the album because they simply weren’t good enough.

‘I did pretty much write an album about being a mum, but that’s boring, so I scrapped it. I thought I’d run out of ideas.’

Her words have ruffled feathers at the highest echelons of the music industry, with one insider saying: ‘The basic problem is that Adele got happy and couldn’t write.

‘Every theme she has had in the past has been a broken relationship and a sad life, and then there she is at 22 with ten Grammys, an Oscar, a Golden Globe, millions of pounds as well as a partner and a baby.

Adele's new album, which will feature this image on its cover, will be released on November 20

‘Everything in her personal life was going right so everything in her creative life was going wrong. She basically lost direction and lost inspiration. She approached a lot of big names in the industry for help and they stepped in. But then she cast aside the work. That’s left a lot of big names furious.’

One of the collaborators was Phil Collins, who was contacted personally by Adele.

He said recently: ‘She’s a slippery little fish.

‘She got hold of me and asked if I would write with her.

‘She gave me a piece of music to finish and at first I didn’t know if I’d failed the audition as I didn’t hear back from her. Then she said, “No, no, I’m moving house and the baby’s taking up a lot of my time. I’m not actually doing anything at the moment.” And now I hear there’s an album coming out. I’m not on it. I know that.’

Adele, who is worth £45 million, also annoyed Blur frontman Damon Albarn, who described some tracks on the album as ‘very middle of the road’.

He said: ‘Adele asked me to work with her and I took the time out for her. And I’m not a producer, so... I don’t know what’s happening really. Will she use any of the stuff? I don’t think so. Let’s wait and see.

‘The thing is she is very insecure. And she doesn’t need to be. She’s still so young.’

The industry executive added: ‘You don’t annoy people like Damon and Phil. It’s not etiquette.’

Other artists who didn’t make the cut include Pharrell Williams, whose single Happy was the most successful song of last year, and renowned songwriter Diane Warren, who has written songs for Whitney Houston, Christina Aguilera and Rihanna. Miss Warren took part in several writing sessions in London in 2014. Last night her publicist confirmed that she ‘has no songs on the new album’.

Adele, 27, has a three-year-old son, Angelo, with her long-time boyfriend, Old Etonian Simon Konecki.

She has admitted that both her debut album 19 and her second album 21 were written during the angst and heartbreak of failing relationships. Released in 2011, 21 sold more than 30 million copies making it this century’s most successful album to date.

A virtual recluse who avoids pop’s star-studded parties, Adele once said: ‘I can’t be a product. I have all the say; I have power over everything I do.’

Another record company source said: ‘Adele does things her own way and is totally unapologetic about it.

‘You can’t say it’s unprofessional because she’s a massive selling artist and she’s a creative but she doesn’t play a team game. The big test will be how the album is received and the reception she gets.’