Adapting a bestselling novel and bringing it to life on stage is always going to be a challenge.

It’s even more tricky when you have to portray the horror of the Battle of the Somme, complete with trenches and tunnels.

A century after the outbreak of the First World War, Sebastian Faulks’ novel Birdsong is on a national tour which includes Birmingham Rep.

It tells the story of young Englishman Stephen Wraysford (George Banks), who embarks on a passionate affair with beautiful French woman Isabelle (Carolin Stoltz).

Then the war breaks out and Stephen must lead his men through the carnage of the Somme and through the sprawling tunnels that lie underground, while clinging to the memory of Isabelle.

Former Blue Peter presenter and veteran actor Peter Duncan plays soldier and expert tunneller Jack Firebrace.

He explains: “Bringing Birdsong to the stage, especially with its setting, is a challenge.

“If we built a real tunnel, you couldn’t see anyone in it.

“So we have a symbolic entrance to the tunnel, then we create the sense of being in it with the clever use of light and echoing sound effects.

“We each carry lamps so we light ourselves, and then there’s the explosions created by sound effects.

“When the bombs go off in the tunnel, the first four rows jump out of their seats.

“So many people have read the book but the play is differently structured and some characters are featured more than others.

“This is the third stage production of Birdsong, it’s been in the West End and on tour before, but it’s certainly not a case of ‘let’s just put it on again’.

“Each production is different and a lot of work has gone into it. The novelist Sebastian comes to rehearsals.

“And this is a special production because of the centenary of the First World War.

Peter Duncan plays Jack Firebrace in the stage production of Birdsong
Peter Duncan plays Jack Firebrace in the stage production of Birdsong

“It’s powerful stuff, about the sheer folly of a genocide of humanity which we seem to be very good at in different forms.

“I know a bit more about the First World War now. We had a Sergeant Major spend three weeks with us in rehearsals, teaching us how to hold a gun and do the drills, and also gave us a flavour of what life was like in the trenches, with the mud, lice and poor food.

“It’s an ensemble cast, I’m probably the most well-known but I’m not billed as the ‘star’ and my name isn’t on the posters.

“So quite a few people have said afterwards ‘I didn’t know you were in it’. Someone said they hadn’t even realised it was me until I did an appeal at the end for Help For Heroes. I am obviously immersed enough in the character to convince people.

“I remind everyone at the end that we still have armed forces fighting today, and ask for donations for the charity Help for Heroes. Although it baffles me why a state employs soldiers and then doesn’t look after them properly. I don’t see why it’s up to the public to raise money for them.

“You only have to look at the Ukraine and Syria to see where the flashpoints are, and you wonder whether more chaos will ensue again.

“Our species is inclined, sadly, to take each other on.”

Peter is probably still best known for being the daring presenter of Blue Peter in the 1980s who did things like cleaning the clockface of Big Ben and running the first London Marathon.

But he went to stage school and was a child actor, and returned to the stage after his stint on television, appearing in shows like Barnum and Me and My Girl.

“I’ve never played the Birmingham Rep before and I’m looking forward to it.

“It’s good that this tour is taking in theatres which aren’t traditional touring venues.

“I don’t like this distinction between proper theatre and commercial theatre. Commercial theatre can be classy too.

“My parents used to put on pantos and I have a great respect for them.”

Peter is married to midwife Annie, with whom he has four grown-up children.

He turns 60 in May but looks much more youthful, and certainly has a lot of energy still.

“I don’t feel nearly 60, but thanks for reminding me! It’s been nagging away at me.

“But no, I will celebrate my birthday, and annoy the younger people by showing I am fitter and sharper than them.

“I stay in shape, I run and play five-a-side football and tennis. As you get older, they tell you to take care and slow down, which I think is a load of rubbish. You just stiffen up if you slow down.

“I got a very nice tweet from a girl the other day saying what a good actor I was and that kind of thing. She didn’t seem to realise I was nearly 60 and old enough to be her father.

“It was a boost. I showed it to my wife, she was very interested.”

* Birdsong comes to Birmingham Rep from March 17-22. For tickets ring 0121 236 4455 or go to www.birmingham-rep.co.uk.