Mathew Baynton talks about playing identical twins, the epic scale of the series and how he would approach the apocalypse.

Can you describe your character?

I play identical twins, Jamie and Ariel, but they have not had identical lives. Jamie is an intelligent and capable man who has experienced a big loss and, to cope with it, he's created a sort of safety blanket for himself in routine. He's almost wilfully trying to not achieve any greatness or happiness in his life, but what he is trying to achieve is a life of absolutely no surprises. So he gets up at exactly the same time every morning, has exactly the same breakfast, goes to work, does his job and goes home, and that suits him very well. Until he finds out the world is about to end and everything changes... It is the catalyst for him to face up to life and its challenges.

Ariel, in contrast, is a young man who's always had a chip on his shoulder and has done everything he can to prove that he is special. He thinks nothing of playing games with people's lives and gets his thrills out of manipulation and danger. When the news of the end of the world comes, Ariel, who's kind of got an anarchist attitude, begins to break some of the big, big taboos.

Is it challenging to play two roles?

The challenge is what makes it fun and that's what you look for with each new project in order to still be thrilled and interested in your work as an actor. What's so fun about it, given that they're identical twins so they genetically spring from the same source material, is that it is almost like playing one character but different sides of one potential human being. It's great, you go to work one day with one thing, then the next day is so different. It's brilliant fun.

What's it like to play one of the leads in a big ensemble that includes such well-known actors?

Being surrounded by brilliant actors just makes it easier, so much of a scene is about being responsive to others. I love meeting great actors and I'm a fan of many of the people I'm working with on this. When people are brilliant around you it's so much easier, because you don't have to create any of the fantasy in your head. It's a pleasure to work with them and to learn from them.

It's funny, because, as Ariel, I've been working with Jenna and Megan and, so far, they've never seen Jamie. And as Jamie I've been working with Joel and he's been really intrigued about Ariel. I'm looking forward to seeing the stories intersect and all the different characters come together.

Jamie and Dave are quite mismatched friends. Have you and Joel been having fun?

We've become really good friends. I have come to love that man very deeply in a very short space of time. He's brilliant on camera and very funny off screen, and that chemistry is so important, because he's the one thing in Jamie's life that brings him any joy. It's such a real relationship between the two of them but Dave isn't just the funny sidekick. He calls Jamie out on being selfish about things, which he is a bit because he's caught up in his own story and he doesn't appreciate that he has this incredibly loyal friend who chooses to spend the end of days helping him sort his life out. That sense of loyalty, I think, is one of the sweetest threads through this show, and it's really easy to play that friendship when you're working with someone who you get on with so well.

Is there an everyday sense of the ambition of this show when you're on set?

Oh definitely, yes. It's expressed most clearly in location really, and that's one of the things I can't wait to see come together. This is a global story and the audience will wonder how the stories in Slough, New Mexico and Rome are related to each other.

You also co-write and star in Sky 1's Yonderland. While that is a very different type of show to this, do you think there are some similarities in terms of ambition?

They're both shows that are ambitious in terms of the risk that's being taken in material that doesn't feel like it has an awful lot of precedent on TV. You get great TV by taking risks and what you need to be looking for is someone who's come up with something brilliant that they really believe in. That was just abundantly clear the moment I started reading the script for this, it was like, 'Wow, he's absolutely gone for it'.

I really believe in writers not considering the reality of production budgets and executive conversations. Iain definitely wrote something that's almost wildly unrealistic to achieve, but that's what's going to make it so exciting, and it's brilliant that Working Title and Sky recognise that and say 'yes, you can cut to the Vatican'. I remember reading that as a stage direction and thinking, wow, this is not a guy who's trying to get an easy commission.

So if there was to be an impending apocalypse, how would you spend your final 34 days?

I would just spend that time with my family, because I don't think anything else would really feel like any kind of priority. I don't really have any kind of bucket list. It would be a very quiet end of days, I think. It might be hard, logistically, to work out how we'd share the time. Christmas is tricky enough when it's a 'Christmas Day with my family and Boxing Day with yours' kind of thing. But on the day the comet hits where are we going to be? You don't want anyone to feel left out.

How would you describe the series to encourage people to watch it?

It's an epic comedy drama. What I really love about it is that it takes the situation very seriously and finds the humour in the face of adversity and tragedy, like in life.