Inbetweeners co-stars Simon Bird and Joe Thomas have teamed up with old friend Jonny Sweet for the World War One-set comedy Chickens (Sky1HD, Thursday) about three young men who are left behind in Blighty while their contemporaries go off to fight in France.

Here, Bird tells TV & Satellite Week what it was like being the only guys in the village…

What can you tell us about your characters in Chickens?

“I play Cecil, who desperately wants to go to war, but he has flat feet, so he’s been turned down by the army, whereas his friends Bert and George have actively chosen not to go to war. Joe’s character George is a pacifist for religious reasons, while Bert, who’s played by Jonny, just likes the idea that he’ll have his pick of the women. It’s your classic odd couple set-up – only there are three of us.”

The three of you wrote this as well as starring in it. Was that difficult?

“I think writing as a three is quite rare. Comedy is usually written by pairs. We had to have a good relationship between the three of us to survive that, because it’s quite a fraught process.”

How did you come up with the idea?

“We didn’t want to set anything in the present day. There have been a lot of very good sitcoms recently set in the real world of the 21st century like Peep Show and The Office. We wanted to create an alternate reality so although Chickens is set in the past we’re still using modern language. We wanted there to be a hint of silliness, so it’s not quite the real world. This is probably the furthest back you can go and it can still feel relatable to the present day.”

What’s changed since this was shown as a Channel 4 comedy pilot, and why did the channel pass on making it a series?

“We’ve learned from mistakes we made in the pilot and everything about the series is better in terms of sets and production values. When Joe was cast in Fresh Meat and I was cast in Friday Night Dinner, Channel 4 went from having one show with us in it – The Inbetweeners – to three. I think the idea of four was a bridge too far.”

What’s it been like working with Barry Humphries, who plays the local headmaster?

“He’s a legend and sometimes we forget how amazing he is. It started out as a joke. Sky asked us who would be the perfect headmaster, and we said ‘somebody like Barry Humphries’. They said: ‘OK, we’ll give him a call.’”

You’ve been working together as a trio in comedy for a while, haven’t you?

“Yes. People assume Joe and I must have met on the set of The Inbetweeners, but this has been a long-term plan. Our background is writing sketches more than standup; our sketches were always very long and wordy. We won’t tell you about any of the other sitcom ideas we had, because it will be too embarrassing for us.”