Gavin And Stacey star James Corden has said he “never ever thought” the sitcom would be a long-running show and that its success had been “a dream come true”.

The 46-year-old added that just having a show that is “worthy of a Christmas special” was enough for him and that he thought ending at three series was the right decision.

Gavin And Stacey: The Finale will air on Christmas Day on the BBC and it will be the show’s final episode following 2019’s festive special which ended on a cliff-hanger when Vanessa ‘Nessa’ Jenkins, played by Ruth Jones, proposed to Corden’s character Neil ‘Smithy’ Smith.

Gavin and Stacey: The Finale
Corden and Ruth Jones were speaking ahead of the show’s Christmas special (Ian West/PA)

Speaking at a screening in London ahead of the Christmas Day episode airing, Corden said: “We’ve honestly never ever thought past what we’ve been commissioned to do, when we were writing the scripts for the first series, we didn’t know if the show would get green lit.

“Then it gets green lit, then you shoot it, and then you’re hoping that someone finds it, then you get to do another series.

“And then suddenly, as that one starts coming out, it feels like lots of people are watching it.

“And then we did the first Christmas special, which was just a dream come true for us, like an absolute dream come true, to have a show that was considered worthy of a Christmas special, that was enough for us is the truth.

“And then we really felt like we probably told enough of the story, and if we’re honest with ourselves, we were finding it hard to construct ways for the families to keep meeting up… And so I think when we ended the third series, it was definite that was it.”

He explained that a finale episode was not certain and there was a chance that he and co-writer Jones would leave the show at its cliff-hanger ending.

Corden added: “We had a week in September, where we were like let’s get together then, and if there’s nothing there, if the characters don’t show us what the story is, it doesn’t matter.

“We haven’t told anybody, we haven’t told the cast, we haven’t spoken to the BBC, and it’s kind of lovely hearing Charlotte (Moore, the BBC’s Chief Content Officer) talk about those moments.

Gavin and Stacey: The Finale
The special will air on Christmas Day at 9pm (Toffee International Ltd/Tom Jackson/PA)

“We didn’t contact Charlotte till we’ve written, I think 70 pages of this special, because by then we felt like, ‘oh, we’ve got something that we feel that we’re ready to share’.

“Because it may sound like a complete nonsense but it doesn’t really feel like we’re in charge of writing, I feel like we just have to be together, and we sort of open a portal and the characters arrive, and they tell us what they want everybody to know.”

The actor, who used to front US talk show The Late Late Show With James Corden, said he felt the show’s success was a “lesson” in “impatience”.

He added: “We’re sort of told now, particularly in television, or the way that we consume stuff, we talk about content and we talk about consumers, and we talk about speed, and we’ve decided that speed is the single most important thing in everything that you can do, I ordered it then, and it arrived then.

“And you get young people now watching things at twice the speed that it was ever meant to be formatted at, and you’re told speed is important, and here’s a show that ended 15 years ago, waited 10 years to tell another hour-long story, and waited five more years to end it.

“And maybe the lesson for all of us is actually, maybe time and patience, and care, might be the answer to things to have a longevity outside of what we consume on our phones.”

Gavin And Stacey: The Finale will air on BBC One from 9pm on Christmas Day and will also be available on BBC iPlayer.

The documentary Gavin And Stacey: A Fond Farewell will be shown at 7pm on New Year’s Day on BBC One and BBC iPlayer.