Mavis Eccleston was brought to production by Grantchester star Tom Brittney and stars Penelope Wilton and Jonathan Pryce as Mavis and Dennis

A split image of Jonathan Pryce, Penelope Wilton and Tom Brittney© Apple TV/Joss Barratt/PBS/ITV

ITV has announced a powerful new drama based on a “tragic” true story is in the works, and it sounds like a must-watch.

Titled Mavis Eccleston, the four-part drama stars Penelope Wilton (After Life, Downton Abbey) and Jonathan Pryce (Slow Horses, The Crown) and follows the true story of a couple who decided to end their lives together in a joint suicide pact. But while Dennis passed away, Mavis survived and was later arrested and charged with her husband’s murder.

The show was brought to production by Tom Brittney, best known for his role as Reverend Will Davenport in Grantchester, who gained the “confidence and trust” of the Eccleston family.

Robson Green and Tom Brittney in Grantchester season 8© PBS Masterpiece
Tom Brittney starred opposite Robson Green in Grantchester

Tom has collaborated on the development of the series alongside screenwriter Chris Lang (Unforgotten, The Thief, His Wife and the Canoe, I, Jack Wright), director Bruce Goodison (Anne, Doctor Foster, Then Barbara Met Alan) and producer Kate Cook (The Cure, Glasgow Girls, The Watchman).

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Mavis Eccleston and her family have worked with the creators throughout the script process and have given their blessing to the upcoming drama, which is due to begin filming in Bristol in June. Keep reading to find out more about Mavis Eccleston…

What is Mavis Eccleston about?

The four-part series centres on Mavis and Dennis Eccleston, who, after nearly 60 years of marriage, decide to make a joint suicide pact after Dennis receives a terminal cancer diagnosis.

The synopsis reads: “Much to the anguish and upset of their adult children, Kevin and Joy, Mavis and Dennis decided to end their lives together when 81-year-old Dennis received a terminal cancer diagnosis and declined treatment to avoid prolonging his suffering. He’d had cancer twice before and knew the gruelling toll the invasive treatment would take on him and his family life.

“Truly heartbreaking events unfold as the family desperately try to dissuade Dennis and Mavis from taking a lethal cocktail of medication, but they remain steadfast in their belief that they should leave the world together.

Dame Penelope Wilton will play Mavis© Alan Chapman/Dave Benett/Getty I
Dame Penelope Wilton will play Mavis

“Having taken an overdose together, they are both rushed to the hospital, where Dennis passes away, but Mavis survives. Following a confused and disorienting interview with hospital staff, the Police are alerted, and Mavis is arrested.

“In the midst of such tragedy, Mavis and her family, whilst trying to process the grief of having lost their father, now face the very real prospect of their mother spending the rest of her life in prison.”

Who stars in Mavis Eccleston?

Penelope Wilton (After Life, Downton Abbey, The Best Exotic Marigold Hotel) and Jonathan Pryce (Wolf Hall, Slow Horses, The Crown) star in the leading roles of Mavis and Dennis Eccleston. Other supporting cast members are yet to be announced.

Jonathan Pryce plays Dennis© Jed Cullen/Dave Benett/Getty Ima
Jonathan Pryce plays Dennis

What have the cast and crew said about the series?

Explaining why he brought the story to production, Tom Brittney said: “When I first read about Mavis and Dennis in 2018, I was struck by the extraordinary love at its heart and the profound injustice their family endured.

“I felt their story, told with care and humanity, could be a powerful drama and a worthy contribution to a debate that remains urgent and deeply complex. Having worked with ITV, I knew they’d be the perfect home as an institution that champions powerful, social justice stories.”

Tom Brittney first met Mavis and her family before bringing the story to Corestar Media© PA Images via Getty Images
Tom Brittney first met Mavis and her family before bringing the story to Corestar Media

Meanwhile, Penelope Wilton commented: “Mavis was devoted to her husband, Dennis, their enduring love for each other clear to see to all. They lived life on their own terms and when the time came, she wanted to respect his wishes.

“The fact she then faced the very real prospect of spending the rest of her life in prison for acting out of love is simply unimaginable. To be asked to bring her experience to life is a huge responsibility and true honour.”

Meanwhile, Jonathan Pryce added: “This is a powerful and timely story of an extraordinary, devoted couple as they face the painful dilemma of assisted dying. We will hopefully honour their deep love for each other and their bravery.”

While a release date is yet to be announced, Mavis Eccleston will begin filming in Bristol in June 2026 and will land on ITV.