What next for The A Word? Christopher Eccleston and Peter Bowker reveal hopes and plans for series 4

So what might have changed by the time The A Word returns for a (potential) fourth series?

Peter Bowker tells RadioTimes.com: "Joe will be a teenager of course - a tricky time to negotiate for any young person. And his parents' circumstances will have changed again – but I am not at liberty to reveal how!

"I also want to tell stories about group living for Mark (Travis Smith) - which will mean new characters with autism including a young woman on the spectrum. And elsewhere of course we have a young couple negotiating the early years of married life in the shape of Ralph and Katie and a slightly older couple negotiating the early years of married life in the shape of Maurice and Louise...

"Rebecca will have challenges of her own as a single Mum and her increased dependence on Tom will take us deeper into their friendship. Rebecca and Tom’s relationship as a study of friendship feels like fertile territory."

He added: "I am hoping the cast will all return to help carry on tracking Joe and his extended tribe through the next stage of his life... When you have a cast as good as these who have inhabited the characters with such joy it inspires you to keep telling new stories."

Eccleston is also firmly on board with a fourth series – especially if it means the show can spotlight the stories of other characters, including Ralph (Leon Harrop) and Katie (Sarah Gordy), who have Down's Syndrome, and autistic young man Mark.

"I think it was always Pete's intention that the boy on the spectrum is the focus," the former Doctor Who actor tells RadioTimes.com. "But as you've seen with the character of Travis and the character of Sarah and with Leon, he's broadened it out to embrace other areas of 'disability' - I hate that word. Neural diversity, really, I think is the way for The A Word.

"So I think there's opportunities for Pete to explore lots of issues as our central character grows. And I think parenting a child on the spectrum becomes, for instance, much more complex when puberty and adolescence and sexuality come into play. And of course our young actor, Max, is not there yet.

"And I think that's to a certain extent why Pete has given very strong storylines to Leon and to Sarah and to Travis... we've now got this wonderful thing of Leon and Sarah's relationship. The marriage obviously is joyous and a celebration but now what these two people are going to have to do and the people around them are actually see that relationship through. And also I think Travis is a wonderful character, so there's so much there."

The actor also has a grand vision of a drama that follows Joe for many years to come – if child actor Max Vento continues to enjoy the project. "I think certainly in terms of Max we could go back to that in 10 years time, couldn't we?" Eccleston suggests. "We could pick it up when he's 15, we could go when he's 25. There's so much scope for it in the way that Boyhood the feature film, the American feature film, did. But I think, even so, we could go into production in a year or so and explore all the issues."

He adds: "I really hope that we do a fourth and a fifth and a sixth [series]. I think there's an appetite for it, clearly, with the audience, and if you look on Twitter. And as with everything in television it depends on ratings and decisions at an executive level.

"But I will be there... and we need to create a campaign for a fourth series!"

All three series of The A Word are available on BBC iPlayer. Check out what else is on with our TV Guide.