The pair told the Radio Times that they are "getting close" to a completed script for the follow-up to 2011's The Inbetweeners Movie.
"Inbetweeners fans are more discerning and vocal than people give them credit for," said Morris. "The last thing any of us wants is a cheap cash-in. At the moment the script is at version 0.5, so we're getting close... but we're not there yet."
The writer continued: "Because the film was genuinely independent, there's no studio breathing down our neck. It's down to us to write a script that we think is worth everyone's time."
Inbetweeners star Simon Bird (Will) previously told Digital Spy that he would "be happy" to consider a new film, but added that the first movie spinoff of the E4 comedy provided "a good conclusion".
"[The cast] get on very well and we trust Iain and Damon," said Bird. "But they'd better hurry up, because I'm getting on for 30!"
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Watch Simon Bird discuss the Inbetweeners sequel below: