'Victoria' creator Daisy Goodwin says the show has the potential to "go on and on".
Jenna Coleman as Victoria
The popular ITV period drama is in its second series and as the two-hour long Christmas special approaches, the writer has been teasing the possibility of a third season.
However, she has hinted that there is the chance a new cast would need to be brought in.
While she has praised Jenna Coleman for her outstanding portrayal of the late Monarch alongside her real-life partner Tom Hughes [Prince Albert], Daisy would love to see Helena Bonham Carter take on the role.
She said: "I hope the series can run through Victoria's reign, I have thought about how it could continue ... I mean, yes, it could run and run...
"[A cast reshuffle] could be possible, [but] I have to say it would be very hard to top Jenna Coleman. I think it kind of depends really on the appetite of the public.
"Helena Bonham Carter would be good.. [But] for now I can only think of Jenna."
Daisy says that a third series would include the revolution in 1848, which would give the show the chance to bring in new characters.
On how a third instalment would pan out, she told Digital Spy: "If there were to be a series three, it would include the revolution which was sweeping across Europe, in 1848, and Victoria and Albert think they're going to lose their throne.
"Albert and Victoria will face a very difficult path emotionally, and personally.
"And there will be lots of surprises, and new characters that you might not know about, and that people won't be expecting. And an interesting new political dynamic.
"I think it will be will all change."
Meanwhile, the Christmas Day (25.12.17) episode, which will go head-to-head with ITV's 'Coronation Street' in a festive ratings war, is set to establish Queen Victoria as a new mother, as she is "learning to balance her responsibilities as both parent and queen".
Daisy said previously: "Victoria is the only Queen Regnant to marry and give birth while on the throne and the challenges of being head of state as well as a wife and mother are legion. In many ways, Victoria's dilemma is a modern one - how do you have a successful marriage and a happy family when you are holding down an important job. Can you really have it all?"
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