Tom McKay: ‘Dirty Business Will Make You Scream With Rage & Cry Your Heart Out’

In July 1999, eight-year-old Heather Preen, her 10-year-old sister Suzanne and their parents travelled from their home in Birmingham to stay in a chalet near the Devon coast. After a day collecting shells and playing at the beach, Heather fell ill – and within just two weeks, she had died. She was infected by E coli O157, a particularly aggressive strain of the pathogen, after hopping over a patch of raw sewage dumped on the beach; her sister was also infected, but remained asymptomatic.

Her tragic story is woven through Channel 4’s new three-part docudrama Dirty Business, which blends actors, real footage and real people to showcase how raw sewage dumping has become standard for England’s water companies: scummy beaches, dead fish, sick children. While Jason Watkins and David Thewlis play Cotswold neighbours Peter Hammond and Ash Smith watching their local river transform from wildlife haven to desolate grey dump, Heather’s story is brought to life by Posy Sterling as her mother Julie and Tom McKay as her father Mark Preen.

In 2024, water companies dumped raw sewage into England’s rivers and seas for 3.6 million hours, and in October 2025, South West Water was rated red for its environmental performance for the 14th year running. The past two instalments of the prestigious Oxford-Cambridge Boat Race have taken place under the shadow of E coli warnings, with rowers reporting illness and vomiting as a result of pathogen concentrations up to 10 times higher than the ‘poor’ threshold.

Airing Monday, Tuesday and Wednesday evening this week, Dirty Business is 2026’s Mr Bates vs The Post Office as families like Heather’s still wait for water companies to be held accountable for their reckless actions. We sat down with star Tom McKay to find out more.

Q&A: Tom McKay On Dirty Business

Tom McKay: ‘I felt an enormous weight of responsibility in telling Mark’s story.’

Hi Tom, how’s life going at the moment?

I’m doing really well, thanks. Far too many plates spinning, not least in the form of a new baby in the house, but I actually prefer to be just on the right side of overwhelmed, so I’m not complaining!

You are about to star in Dirty Business – can you give us an elevator pitch for the show?

Dirty Business is a meticulous, intelligent, compassionate and fearless take down of the dubious practices of the privatised water companies in the UK. If that makes it sound dry (no pun intended), it’s not. Our incredible writer/director Joseph Bullman has a brain the size of a planet and a heart to match, so he’s put together something that will make you scream with rage and cry your heart out.

I was on a plane when I read the scripts, and I think the person next to me thought I was having a breakdown – it’s incredibly upsetting and enraging. But somehow Joe has also managed to find the humour in the midst of the madness, so it’ll also make you laugh out loud.

You play Mark Preen – how would you describe him? What responsibility did you feel in bringing a real person like Mark to life?

I felt an enormous weight of responsibility in telling Mark’s story, especially given the gravity of what the Preen family went through. It’s impossible to describe the Preens in terms of character because they are of course real people who have suffered unimaginably. What I will say is that they were exceptionally generous in terms of communicating with me about their experience, along with their family dynamics, so that we could tell their story with as much authenticity, specificity and honesty as possible.

What was it like preparing to tell a true story?

On the one hand it was very intimidating because of the weight of what they were all subjected to. However, Joe and our amazing Executive Producer Laura McCutcheon, conducted their research with such care and respect that I always knew we were being steered in the right direction, and in a way that would honour the people whose stories we were telling.

Tom McKay: ‘I hope audiences honour Heather’s memory by lobbying for change.’

How did you get into character?

There were three main channels. The first and most important was a series of conversations I had with the amazing Suzanne Preen, who is Heather’s older sister. She was so generous with her time and gave me a huge amount of information about Mark and what they went through as a family, alongside details like jokes they shared, his hobbies, his favourite music.

Secondly, I always had Joe who, alongside being the most empowering director I’ve ever worked with, had spent a lot of time with the real people, so was always able to discuss Mark’s state of mind in any given scene with real compassion and precision.

Finally, the massively talented Posy Sterling (who plays Julie Preen) and I spent a ton of time together, sometimes talking at length, sometimes in total silence, but always just being together and forging the foundations for this marriage that was put through so much.

It’s a heavy subject. How did you find lightness on set?

Honestly, on this job there wasn’t a huge amount because of the nature of the story we were telling. When we were on location, Posy and I had a couple of meals together where we chose to switch off completely and not talk about the work, but pretty much all the time on set was incredibly focused and not especially light; but it would have been strange if it was any other way, given the story we were telling.

Joe asked us to stay in the accent throughout (the Preens are from Birmingham), in part so that the girls playing our daughters never heard us speak in our own accents, to help them suspend their disbelief. I’ve never done that before and it does mean you’re automatically more immersed in the work, hence the intense working environment and focused atmosphere on set.

What do you hope audiences will take from it?

I hope audiences will be fired up and motivated to help create change. To not sit back passively and allow the water companies to continue to act with such impunity. And ultimately to honour Heather’s memory by lobbying for change.

Tom McKay: ‘The massively talented Posy Sterling (who plays Julie Preen) and I spent a ton of time together, sometimes talking at length, sometimes in total silence.’

You’ve also got series 2 of The Undeclared War coming up. What can you tell us about that?

The new season is still executive produced by the brilliant Peter Kosminsky (who has always been a hero of mine), but this time it’s written by the superb Colin Teevan, who I’ve previously worked with in theatre. Alongside our fantastic new director, Paul McGuigan, he’s kept all the political sharpness and prescience of the first season, while also opening up other geopolitical storylines that make it feel just as raw and alive.

We’re also joined this season by the amazing Sian Brooke. We were at National Youth Theatre together (a thousand years ago, when we were actual youths!), but had never worked together properly before, so that was a real treat.

What does Max K have in store this time?

Well, given that it’s a world of intrigue and cyber espionage, that would be telling!

Any roles in the pipeline that you’re excited about? (If you’re allowed to tell us!)

Yes, but sadly, like Max K, I’m sworn to secrecy!

What has been your favourite project to date?

That’s such a hard one to answer! When I left drama school, I did only theatre for nearly a decade, and playing Brutus in Julius Caesar was a definite highlight as I grew up near Stratford-upon-Avon and have always loved Shakespeare. But I get pretty immersed in every job I do so my favourite job is usually my most recent – so I’ll be biased and say Dirty Business.

Who has been your favourite actor to work with in the past?

Eesh, that’s also a really hard one to answer. I was very lucky to play Billy Paxton’s son in a show called Hatfields and McCoys; besides being the most fearless actor he was honestly just the most lovely man. We shot in Romania for six months and he would take me out on random day trips exploring. I subsequently used to spend time in LA and he was a real anchor of support for me in that crazy town. I will never forget his kindness.

Which co-star did you learn the most from?

It’s impossible to pick one. I learned about leading a set from Bill, about detail and grace from Mare Winningham, professionalism and precision from Simon Pegg, humility and humour from Maxine Peake, confidence and poise from Li Jun Li, fearlessness and intelligence from a young Luke Thompson, courage and conviction from Posy… I’ve been really lucky with the people I’ve worked with, and have never had to work with anyone especially difficult.

What’s your dream role?

Macbeth or Iago.

Tom McKay: I spend loads of time at home which is my favourite place to be. (© Ron Timehin)

What’s a genre you’d like to do more of?

I’d like to do more historical stuff. Being on historical sets in amazing costumes definitely brings out your inner six year old.

Who is an actor, writer or director you’d love to work with?

So many! In theatre, Robert Icke, James Graham and Rebecca Frecknall; in TV, Jack Thorne, Sally Wainwright and Russel T Davies; in film Christopher Nolan, Steve McQueen, Chloé Zhao… Can I keep going? I quite like this game.

Do you get to spend much time at home?

I spend loads of time at home which is my favourite place to be. I’ve been really lucky in that I’ve travelled a lot for work since my kids were born, but I’ve almost always taken the family with me – my daughter had lived in Rome, Prague, Buenos Aires and Montevideo by the time she went to school. I’d barely left the West Midlands by the time I was her age!

What are your hobbies?

Cold water swimming. Yep, I’m one of those people. Sorry.

How do you find balance in your personal and work lives?

I absolutely love my job, but my family come first. Always. Not sure if that counts as balance!

How can we all live a little bit better?

I got on social media for the first time last year, having completely resisted it for 20 years since the advent of Facebook. I was suddenly aware how distorted and angry the world can appear through the lens of socials. So probably get off our phones and be a bit gentler with each other!

Anything fun in the pipeline – professionally or personally?

I’m hoping to do a ‘Paddle Out’ in May alongside the amazing Julie Preen in support of Surfers Against Sewage. That should be a lot of fun as well as most importantly helping to raise awareness. (Julie and I are convinced our limited paddling skills will result in our surfboards just going round in circles, but we’ll see how we go!)

Tom McKay: ‘I absolutely love my job, but my family come first.’ (© Ron Timehin)

What Tom McKay Is Loving Right Now

I’m currently watching… Waiting For The Out by the brilliant Dennis Kelly. It’s very good.

What I’m reading… The Mr Men/Little Miss books on repeat, nightly at 7:30pm. Some have aged well. Some…have not!

The last thing I watched (and loved) was… The Ballad of Wallis Island (2025)

What I’m most looking forward to seeing… Summerfolk at the National Theatre directed by the brilliant Rob Hastie.

Favourite film of all time… The Goonies (1985)

Favourite song of all time… ‘A Certain Romance’ by Arctic Monkeys

Band/singer I always have on repeat… Amy Winehouse. I don’t think I’ll ever love anyone’s voice more than hers.

My ultimate cultural recommendation… Walks along the South Bank in London, just seeing where you end up. Wherever it is, there’ll be something cultural involved.

Cultural guilty pleasure… Heated Rivalry. Believe the hype.

Tom McKay stars in Dirty Business, airing tonight (23 Feb) at 9pm on Channel 4.

WATCH