LONDON >> In the rural village of Ambridge on the British radio show “The Archers,” nothing much changes, and listeners like it that way.

They find comfort in the pace and traditions of country life, and in the villagers’ peccadilloes intertwined with conversations about badger culls, jam making, the campaign to save a local shop or a cow’s giving birth to triplets. Class differences, when they surface, are usually respected.

Yes, over the nearly seven decades that the BBC has broadcast the program, plots have included at least one same-sex marriage, the wedding of a Hindu woman to a vicar who rides a motorcycle and a child’s birth out of wedlock. And yes, some characters have turned out to be snobs, bigots, adulterers and even criminals. But the show’s old tagline — “an everyday story of country folk” — still seems appropriate.

Yet a trial that begins on Sunday’s episode has much of Britain buzzing and has divided listeners. The defendant, Helen Titchener, is charged with trying to kill her husband, Rob, after years of abuse.

“The Archers,” on BBC’s Radio 4, is a national institution: Almost 5 million Britons tune in every week to listen to the daily 12 1/2-minute episodes.

“It’s very British, in that not very much happens,” said Clive Aslet, a former editor of Country Life, a 120-year-old magazine about luxurious lifestyles in the British countryside. “That’s one of its essential charms.”

So it was something of a shock when the producers introduced a story line about domestic abuse, which they say is the most disturbing plot twist since Grace Archer, the matriarch, died while trying to rescue her horses from a stable fire.

That was in 1955.

Some applaud the program’s willingness to take on real-life issues, while others yearn for the predictable safety and colorful familiarity that have made “The Archers” so enduring.

Helen, a fragile character whom the audience has known since childhood, and Rob live in the idyllic Blossom Hill Cottage. But it is far from blissful. Rob’s verbal and occasionally physical assaults pushed Helen to the edge of a breakdown. The drama reached a climax in April when she finally snapped and stabbed him. That pushed the weekly audience well over 5 million, including digital downloads.

Five months later, as if following the timetable of an actual case, listeners will hear her appear before a judge, charged with attempted murder.

The villagers remain split over what, or whom, to believe, with many characters having proclaimed Rob a hero for saving three people during a flood in 2014.

“It’s maddening,” said Peter York, a social commentator. “Every decent Englishman feels, how can this bastard be tolerated? Let’s get some incriminating evidence on him! We’re all rooting for her. But it does make one want to throw things at the radio.”

The long buildup to the trial, which has taken more than two years, “is a British type of endurance test,” York said, “except it has never been this long.”

Some listeners have accused Sean O’Connor, the show’s departing editor, of sensationalism. The theme, they say, is inappropriate for a program that was originally intended to encourage farmers to increase productivity amid the food shortages and rationing in the years after World War II.

In The Telegraph, Timothy Watson, who plays Rob Titchener, praised the program for undertaking a difficult issue, but acknowledged, “I know it has been difficult listening, and there is a proportion of our listeners who have struggled with that.”

The program has received considerable acclaim for its realistic portrayal of domestic abuse, which often begins innocuously. In “The Archers,” it started in February 2014 when Rob refused to eat a special meal that Helen had made for him.

“We’ve been taken down a dark path,” said Lyn Thomas, a professor of cultural studies at the University of Sussex, who is contributing to a book about the show. “It has brought to public consciousness an issue that is hidden and where it’s very difficult to get convictions.”

The National Domestic Abuse Helpline has seen a 20 percent rise in calls over the past year, according to Women’s Aid, a charitable group, which attributes it to “the ‘Archers’ effect.” One listener even set up a fund in Helen’s name to raise money for victims, attracting more than 100,000 pounds, or about $133,000, in donations.

Women’s Aid and Refuge, another domestic violence group, advised the BBC as the episodes were written and produced.

John Yorke, a former acting editor for “The Archers,” told The Guardian that “the trick with ‘The Archers’ is that you can only bring in these story lines very, very, very rarely.”

“If you start doing them on a regular basis, you destroy all sense of plausibility, and the strength of that show is the illusion of plausibility and the illusion of everyday life,” he added. “You need to get as much jeopardy about jam making as you do about serious social issues.”

The bucolic English countryside remains deeply embedded in the national psyche. Britons “think of the countryside as being the good days and the city being the bad days,” a notion dating from the Industrial Revolution, Aslet said.

“Broadly speaking, it is a comfortable and a familiar world which people look to at a time when everything else in Britain is changing very rapidly,” he said. “It’s a reassuring soundtrack.”