The Archers: BBC Radio 4, 7pmThe Archers: BBC Radio 4, 7pm

TAMSIN GREIG is very familiar with everyday stories of country folk after spending nearly 20 years as Debbie Aldridge in radio’s The Archers. Now she’s down on the farm once more, this time on the big screen in her first major film role.

The movie is Tamara Drewe, based on the graphic novel by Posy Simmonds that drew its inspiration from Thomas Hardy’s classic Far From The Madding Crowd and brought it wittily up to date.

Olivier Award-winning actress Greig jokes that director Stephen Frears said a couple of times on set that the only reason she was there was because she knew about farming. “In fact,” Frears interrupts jokily, “she knows nothing at all about it.”

Greig understands why he says that.

“He was promised that I knew something about the countryside because I’ve gone like that (she motions with her arm) up a sheep on the radio.”

Tamara Drewe marks her biggest film role after work on TV, including comedies Love Soup and Green Wing, and in the theatre, with an award-winning performance in the Royal Shakespeare Company’s Much Ado About Nothing.

She’s happy to be told that she looks nothing like the novel’s depiction of Beth Hardiment, who’s described as “attractive in a middle-aged earth mother sort of way”. She cooks, cleans, gardens and farms at a writers’ retreat while her detective novel-writing husband cheats on her.

“People did actually think that was my hair, and I thought that was brilliant,”

she says of the wig she wears in the film.

But, despite the physical differences, she was pleased to have the novel’s illustrations for reference.

“I was really delighted to have that as source material because, as an actor, you’re always looking for the shape of the character.

“So, it was really good to be able to go to various drawings. Posy is so delicate and subtle in the way she portrays characters that it’s a real clue of how to play a scene, just by the curve of the shoulder, or a bit of hair.

“Beth very rarely shows both eyes, there’s a lot of hair going on. So it was really interesting to see what tale she was telling by what she was covering up.”

Greig’s done films before, but reckons her parts were so small or she was so unrecognisable “that in years to come you’ll laugh and go, ‘ha, ha, ha, there she was’.

I think I was a middle-aged woman waiting to happen and Stephen Frears saw that and had the vision to put me under that hair. And I’m absolutely thrilled.”

Frears was the reason she took the part. “Ask any actor, ‘Do you want to do a film with Stephen Frears?’ and there is no actor that will say no,” she explains.

Greig went with Frears and the rest of the cast – which includes Gemma Arterton and Dominic Cooper – to the film’s screening at the Cannes film festival.

She says: “Stephen has said all the time he just wants people to go to the cinema to enjoy themselves and I think you do really enjoy yourself when you’re watching it, however awful and funny it is.”

Tamara Drewe (15) opens in cinemas next Friday.

The Archers: BBC Radio 4, Monday to Friday, 7pm.