It’s not often you hear William Shatner’s ego described as “too small”, but that’s the complaint being made by the producers of his latest movie venture, a biopic of Donald Trump.

The movie has been in the pipeline ever since the election last year, but has been fraught with difficulty.

“Firstly we’re going for historical accuracy,” director Steven Spielberg explained. “Which means we have to filter out the lies about him, especially the ones he tells himself. There’s so much sh*t to wade through, the script has been very difficult to write.”

The script is going to be a no-holds-barred, warts-and-all look at his entire life story, billed as a modern equivalent to Ben-Hur, starting with his bith and formative years right up to his election victory in 2016. William Shatner was quickly signed on to play the lead, but has since been let go.

“Bill doesn’t have a big enough ego for the part,” Spielberg explained. “We realised this pretty early on, and god bless him he gave it his best shot, but he just doesn’t have sufficient levels of arrogance. I mean, the amount of ego required for this part is, well, really, really bigly.”

Shatner himself found the whole incident amusing.

“I’ve been called a lot of names in my time,” the 86-year-old admitted, “but this is a new one on me. I must say, to be let go for not being arrogant enough is great, it’s something I can finally tell my grandchildren. They’ll never believe it!”

So who can step into Shatner’s shoes?

“Well, we’re looking at Tom Cruise for the part,” Spielberg answered. “He’s also younger, so will be able to play more of the part, so we won’t have to hire another actor for the middle years.”

Justin Bieber has already been signed on to play Donald Trump during his younger years, and Spielberg has nothing but praise for the young singer.

“A lot of people were critical of the decision,” Spielberg explained, “saying why cast him when he’s a singer, and not even a good one, but he’s taken to the part like a fish to water. I really believe he was born to play this role. There really is no acting required.”

Exactly when the movie will be finished remains a mystery, but Spielberg and his team remain optimistic.

“Can we make this movie?” he asked, then answered, with a gleam in his eye that showed he knew full well the irony of his next three words, “yes we can.”