But for Newcastle author, Nick Milligan – a former Maitland Mercury journalist – the praise is both flattering and devastating, given the storyline of the film bears an uncanny resemblance to the plot of his debut novel.

Mr Milligan began writing Enormity a decade ago, and published it as an ebook in 2013. In Enormity, the main character - Jack - finds himself on a planet almost identical to Earth.

"He passes off classic music as his own material, including that of The Beatles, and the story explores the consequences of that lie," Mr Milligan said.

In Yesterday, the protagonist - also Jack - has an accident and wakes up in a version of Earth in which The Beatles have never existed except in his mind.

"He passes off their classic music as his own material, and the story then explores the consequences of that lie."

Mr Milligan, who is also a movie reviewer, first learned of the new Danny Boyle-directed film in September last year.

"When I read the premise of Richard Curtis' screenplay, my heart sank," he said. "The similarity to Enormity's central idea was very apparent. 

"But when the first trailer arrived this week and I learned the main character's name is also Jack, and the way the trailer depicts the character's arc, I felt the similarities were too large to ignore."

Mr Milligan said as an independent author, one of his marketing techniques since publishing Enormity on Amazon was to do giveaways. 

"This is a means of finding an audience for subsequent books and garnering positive reviews on Amazon that assist in further sales," he said.

"Over a number of giveaways, I've had as many as 20,000 downloads by people from around the world."

Mr Milligan said while it might be unlikely his story had made its way to Hollywood, it was not "completely implausible" given the volume of downloads the book had since its release.

"It must be said that Enormity is a far darker, more abstract and adult version of this morality tale," he said.

"So there is a tonal difference, but the fundamental premise is near identical."

Mr Milligan is now considering his options. 

"I don't like the idea of legal action against a director I greatly admire in Danny Boyle. I think he is exceptional. But I have to consider the damage that Yesterday may do to any aspirations I have in getting Enormity adapted into a movie some day. What was once a premise considered highly original, now appears to be a copy of an Ed Sheeran movie."