A feature-length show is set to air on Radio 3 on Christmas Eve at 7.30pm, and a repeat performance will be scheduled for BBC Radio 4 on Christmas Day at 1.30pm, narrated by Stephen Fry.

When he was approached by the BBC, Mr Blake, 82, who was awarded an OBE in 1994 for services to music, told them that rearranging his Christmas composition in vocalise would be a desecration of his work.

He said: “Last August, BBC’s music producer Jonathan Manners asked me if I would give my approval to a new arrangement of the complete soundtrack of The Snowman.

“He wanted to arrange the entire 26 minute composition in vocalise after he heard my a capella choral arrangement of Walking in the Air which I arranged for Peter Auty and the St Albans Cathedral Choir in 2019.

“I told him he was mad to vocalise the whole thing, but he’s going ahead with it anyway.”

Initially, Mr Blake refused to allow permission to do his composition in vocalise.

“I said it’s impossible to do it in vocalise so if you try and do it without instruments, I refuse”, he explained.

‘I’ve already told Prince Charles’

However, when Mr Manners told him the new arrangement had piqued the interest of royalty he relented.

“When I refused, Jonathan [Manners] told me – it’s very difficult, I’ve already told Prince Charles and the Queen about it – how could I refuse?”.

The BAFTA-winning film, which was also nominated for an Oscar, first aired on Channel 4 in 1982, and has been shown every year on Christmas Day since.

The short film was based on the Raymond Briggs book of the same name about a boy who builds a snowman which then magically comes to life.

The four-minute song Walking In The Air is the only part of the film with words, but is arguably what rocketed the film to its extraordinary success.

The snub has left Mr Blake reeling. “They might be re-imagining my work at Christmas,” he said, “but they still aren’t actually working with me – it will be producer Jonathan Manners who will be arranging The Snowman in vocalise. He’ll be the one who will get the credit for arranging it, not me”.

Mr Manners is the BBC’s Singers, Chief Producer and Artistic Director with a long history of working with choirs and orchestras having been formally educated at the Royal Birmingham Conservatoire.

Vocalise is a musical style that has no words at all – just “oohs”, “ahhs” and “hmms” which are sung by a choir.

These a capella sounds replace the noises usually made by the strings, woodwinds, brass and percussion all usually found in a musical score.

One notable example of vocalise is the Humming Chorus from Puccini’s opera, Madame Butterfly, which features in the scene at the end of Act II as Chio-Chio San (Madame Butterfly) waits for an American naval officer called Pinkerton.

This technique – heard in most families’ kitchens over the Christmas period as the legendary tune is hummed and whistled while the turkey cooks – will now be used to professionally recreate the sounds.

‘I would kill him on the podium’

This week, rehearsals for the BBC’s version of The Snowman will take place with a full choir at a studio in London’s Maida Vale.

Mr Blake said: “They are starting rehearsals tomorrow, but I wouldn’t go along because I would kill him on the podium.

“George Bernard Shaw once said: Hell is full of musical amateurs.”

The song was born out of a stressful time for Mr Blake who wrote Walking in the Air when he lived in a rented beach hut in Cornwall for two months having left his home in Knightsbridge while suffering from stress.

Grammar school-educated Blake, who was the son of a postman from Brighton, claims the new Christmas arrangement is the first time the BBC have recognised his work which he believes is because, “I didn’t have an upper class upbringing like most classical composers” he said, adding “they thought I was too commercial because I wrote advertising jingles before I came to international fame after writing Walking in the Air, despite the fact I wrote the score for The Avengers, Flash Gordon with Queen, and I was commissioned by the Philharmonia to compose Princess Diana’s 30th birthday concerto at the Royal Festival Hall”.

A BBC spokesman told The Telegraph: “The BBC Singers are honoured to work with Howard Blake on a special project as part of our Christmas line-up, details of which will be released to our listeners nearer the festive season.”