While “La La Land” is the toast of Hollywood, with a record-tying 14 Oscar nominations, there’s an internal war over the casting of the hit musical at power agency CAA.

Miles Teller and Emma Watson — both repped by CAA — were originally tapped as leads in the movie, but Hollywood insiders said both lost the roles for being too demanding.

One movie insider said, “Miles was offered $4 million to star in ‘La La Land,’ but he said he wanted $6 million. Watson was offered the lead female role, but she initially wouldn’t commit. Then she began making all these crazy demands, like rehearsals for the film must be done in London — for a film called ‘La La Land’! They jumped through hoops to make it work with her, but she just didn’t feel the film was right for her.

“Producers finally cast Emma Stone — and once she was on board, Ryan Gosling jumped at the chance to work with her again.”

The source added, “Now both Miles and Emma Watson are raising hell with their agents for not securing the roles for them — even though it was the actors’ fault for being too demanding.” British actress Watson — best known for playing Hermione Granger in the “Harry Potter” films — began her negotiations when she was represented by rival agency WME, but signed with CAA in December. Other sources insist she stepped away to do Disney’s live-action “Beauty and the Beast” film.

Another insider added, “Both Miles and Emma f–ked themselves over for not doing ‘La La Land.’ Now that it’s winning all the awards, they’re freaking out and looking for someone else to blame.”

In 2015, Teller told GQ that his agent said director Damien Chazelle dropped him from the movie: “ ‘Damien . . . no longer thinks you’re creatively right for the project. He’s moving on without you.’ ” Teller then sent Chazelle a text saying, “What the f–k, bro?” Chazelle later confirmed that “there was a moment where [Watson and Teller] were doing it. And neither of those casting things wound up lasting or working out.”

Reps for Teller, Watson and CAA didn’t comment.