The writer told The Independent that some lines in the '50s-set BBC drama "haven't worked".
"When a line of dialogue jars and is seen as an anachronism, one holds one's hands up," said Morgan. "But more because it has taken an audience out of the drama. The Hour is escapism and for that moment the escapism hasn't worked."
Some critics have pointed out that the series includes phrases, such as "bottled it", "I'm on it" or "going for a Chinese", that would not have been in common usage back in the 1950s.
"I approach writing a period piece as I would approach all my other projects, focusing on the truth of the characters' journeys but primarily it is a fictional world," explained Morgan. "The past is another country [and] I write as an intrigued foreigner inspired by a new landscape."
She continued: "I am a dramatist. I elaborate. I imagine. I tell a story. And hope it will be enjoyed."
Morgan recently revealed that she has planned for a second series of The Hour, citing "the launch of Sputnik, the birth of CND [the Campaign for Nuclear Disarmament], the anti-nuclear movement" and "racial tensions" as possible themes for future episodes.
The Hour concludes tomorrow night at 9pm on BBC Two, while new episodes air on Wednesdays at 10/9c on BBC America.
> The Hour Episode 5 - recap
Watch a clip from The Hour below: