Back in 2015 saw Matthew Vaughn sign on for a new Flash Gordon movie; however, nothing has been heard of the movie since.
Now while promoting Kingsman: The Golden Circle, Matthew Vaughn is asked about Flash Gordon by Collider, in which Vaughn blames both Guardians of the Galaxy and Star Wars for his Flash Gordon not happening.
“Yeah, we’ve been working on it. For me, the only problem with Flash Gordon is Guardians [of the Galaxy] kind of stole what I would have liked to have done with it. You’ve got Star Wars, you’ve got Guardians, so you’ve got to have your own space opera, but you have to find something that can survive among these two very, very great franchises.”
Regarding having your own space opera, somebody correct me if I am wrong, but the original Flash Gordon stuff wasn't like the 1980 cult classic movie, which similar to Gunn's Guardians of the Galaxy, took a goofy approach to the material.
The original Flash Gordon was more straight-up science-fiction, and not "Go, Flash Go!" or dancing Star-Lord.
Maybe therein lies your own space opera, Matthew Vaughn?
Regarding Star Wars, it's more on the fantasy side of things than hard science-fiction.
Don't know the difference? Watch episodes of Battlestar Galactica.