Is the Salt Path based on a true story? Jason Isaacs and Gillian Anderson on new film

But rather than succumb to these pressures and give up, the pair chose to walk the South West Coast Path in what proved to be a hugely revitalising experience that saw them embrace the kindness of strangers along the way.

Read on for everything you need to know about the true story, including exclusive input from Anderson and Isaacs.

Is the Salt Path based on a true story?

Yes – the film is based on the true story of couple Raynor and Moth Winn, as told by the former in a memoir of the same name. It follows them as they trek the 630-mile coastal route called the South West Coast Path after the couple had been evicted from the farm on which they lived.

In the same week that they had been left homeless, in August 2013, Moth had been diagnosed with a terminal condition called Corticobasal Degeneration (CBD), and when Raynor spotted a copy of the Southwest Coast Path guidebook, she has explained that it felt like their last chance of freedom.

Although Moth's condition was worsening every day at the start of their trek, he started to regain his physical and mental well-being the longer the walk went on – and is still alive more than 10 years on, despite having initially been given a maximum of five years to live when he was initially diagnosed.

The script – written by Rebecca Lenkiewicz – largely sticks to the true facts of Raynor and Moth's story despite containing one or two liberties, with Raynor explaining: "The final script was beautiful, capturing the essence of the original story while taking it forward on a powerful new journey."

Of course, both Gllian Anderson and Jason Isaacs have played real people before – from Margaret Thatcher to Cary Grant – but speaking exclusively to RadioTimes.com the pair explained that the process was slightly different when it came to playing people who are not in the public eye.

"It's definitely less stressful, less pressure," Anderson explained. "You want to, obviously, do right by them and to be respectful in your impersonation. But at the same it's not quite as intense as doing somebody who's in front of the public eye as much as say a Thatcher or Emily Maitlis or something."

"Because the public aren't going to go, 'Well, that's not like them,'" agreed Isaacs. "But also, we really like them. Ray and Moth are amazing people, and their story is so inspiring. The books are so successful, and rightfully so, because they contain messages of such hope and belief and compassion.

"And so you not only want them to feel glad that we're doing it, but you want the audience to feel what we felt when we met them, when we read their stories and to be as moved and inspired by their story."

When it came to meeting the real Raynor and Moth, Isaacs explained that he was less interested in copying mannerisms and more so in understanding what it was that made the couple tick.

"I'm never gonna be as tall, handsome, smiley [as Moth], he's just an extraordinary man," he said. "So I just wanted to know, 'What is it inside him?' One of the things I got when I met him is the sign that he wanted everyone else to feel comfortable.

"He makes a joke of everything, even when he was talking to me at great length about this tremendous indignity and terror of his condition and where it will naturally end, he wanted to make me feel at ease. So he made me laugh all the time about it. That's a quality I recognised and could walk away with."

Meanwhile, Anderson explained that listening to Raynor read the audio book version of her memoir was one of the most useful experiences for her when it came to inhabiting the character.

"It felt like I was properly immersed in her rhythm and her personality," she said. "Her accent is quite unusual. Both of their accents are quite unusual. And I found it very challenging.

"So I think at the end of the day, you kind of choose what feels organic and isn't forced, and hope that that's enough of an impression that that they can recognise themselves."

The film takes in some beautiful scenery, and it's clear that nature is a very important aspect of the story, but Isaacs explained that "it's not just nature" that is important.

He said: "It's the nature you find in that particular place, [which] is a huge part of the story for them. But as much as it's gorgeous to watch as an audience and for us as actors to experience, it was challenging and terrifying for them.

"I mean, life was terrifying. Their future was disappearing, but it was cold and they were hungry and they didn't know what was around the corner. And they had to strike the tent every morning before dawn, because people would come along and be very aggressive to them."

Of course, one aspect that made life terrifying was Moth's condition, but the other aspect was the fact that they were homeless – a fact that sometimes led people to behave towards them in something of a hostile manner.

And the stars have explained that they hope one of the key takeaways from the film is a shifting attitude towards homelessness.

"I think that's one of the things that that Ray and Moth are really keen that people are left with," Anderson said. "Their perception of homelessness and people who are homeless, and to be more compassionate.

"Even stepping into and pretending to experience what they have, you get the impression that you actually have no idea. That anyone who hasn't experienced that probably doesn't really understand the sense of potential hopelessness."

"And invisibility," added Isaacs. "And how open you are to abuse. I mean, the film is very positive, because her book is very positive, right? It was written as a memoir, as a gift to Moth.

"But actually, in their experience talking to them, [and] there's an indication of it early on [in the film]... there's many acts of kindness in the film and those things they remember, but they also experienced the other side of that – from both authorities and individuals – a lot.

"Ray texted yesterday to me that one of the things she hopes people get from the film is they will look twice at people sleeping in doorways and think about them as fellow human beings."

The Salt Path is released in UK cinemas on Friday 30th May.

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