The Archers airs 15,000th episode

June Spencer as Peggy Archer and Denis Folwell as Jack from 1951

The Archers has aired its 15,000th episode with the climax to a plotline that has outraged some of the BBC Radio 4 drama's devoted audience.

Many listeners will have been relieved to hear that Ruth Archer decided not to cheat on her husband, David.

The controversial storyline has had millions waiting to find out if Ruth would consummate her relationship with Sam the herdsman.

The show is believed to be the longest running soap opera in the world.

Night of passion

The Ruth Archer adultery plotline prompted many fans to complain to Radio 4.

One listener wrote to Radio 4's website, saying: "I thought The Archers was supposed to be a radio series with an agricultural theme, not an audio version of a Jackie Collins novel."

In the anniversary episode, Ruth headed off to Oxford for a night of passion with Sam in a hotel room. But at the very last minute she decided not to go through with it.

People feel they own a part of the series Actress Hedli Niklaus

Hedli Niklaus, who plays Kathy Perks, said: "It's hard to be all things to all people, to keep established listeners happy and attract new ones.

"I think that people caring about the characters is a good thing, but so is having their comfort zones challenged once in a while."

She added: "People feel they own a part of the series. We always say there are nearly 5m listeners and there are 5m versions of Ambridge out there."

And editor Vanessa Whitburn told Radio 4's PM programme The Archers was about far more than controversial storylines.

"What people love about the programme, I think, is that as well as these strong slightly racier stories there's a real sense of the passing seasons, there's a real charm and actually funnily enough the things that grab listeners sometimes are the quieter stories," she said.

The show was first broadcast in the Midlands on Whit Weekend in 1950 and went national a year later.

It was originally aimed at a farming audience but despite widening its appeal it still has an agricultural story editor.