Line of Duty is officially the BBC's most-viewed drama: 8 things we bet you didn't know about the hit show

You'll want to read up on these.

Line of Duty facts
(Image credit: BBC/World Productions/Steffan Hill/Geraint Williams)

You'll want to read up on these.

It feels like the whole world and their nan has caught the Line of Duty bug.

A bit like the Friends reunion show, it sure feels like it's been all anyone's talked about for the last month or so. It may just be lockdown boredom, but the proof is in the stats: the show’s popularity has almost doubled over the last year, with figures showing the first episode of the sixth series broke BBC records with an all-time high audience figure of 9.56 million.

So, as the sixth season of the hit BBC crime drama nears to an end, we've turned into our own detectives and delved deeper into the show's history. Keen to discover what truly happens behind the scenes? Keep reading.

*Warning* Contains spoilers! 

Line of Duty facts: A photo of a cast member on the show

8 Line of Duty facts we bet you didn't know

1. Can you spot Jed Mercurio?

Did you know? Line of Duty writer Jed Mercurio made a secret cameo in one of the episode So, can you spot him? Spoiler alert: probably not.

In 2020, Mercurio tweeted that he was the one driving the grey Golf in front of Lennie James and Gina Mckee. His Tweet shared: “No one on set knew the route we’d recce’d, so Lennie followed me through the streets of Birmingham while they filmed the scene in the car behind”.

Who knows - maybe in future episodes, Mercurio will make more of an appearance. For now, we'll be paying close attention to who may be behind the wheel...

2. No one knew Martin Compston was Scottish

Scottish actor Martin Compston, who plays Steve Arnott in the series, is a fan of method acting, whereby you continue to stay in character even when the cameras stop rolling.

For the entirety of Line of Duty filming, it's been reported that he spoke with a London accent. When they finished recording season six, it's reported that Martin surprised the whole crew with his native Scottish dialect.

Line of Duty facts: An assortment of the cast members

3. Lockdown weight gain for DI Arnott

When the UK - and subsequent world - was first hit with coronavirus at the beginning of 2020, Martin Compston returned to his home in Vegas.

During the lockdown, he himself says he 'ate too much and drank too much', meaning that when he returned to filming, his iconic DI Arnott waistcoats no longer fitted.

“That was a really tough day, I was bursting out of everything," he shared. Vicky McClure, who plays Kate Fleming in the series, teased that Martin 'had to get an exercise bike for his flat and [only eat] soup for two weeks'.

4. One messed-up audition led to a huge success

Vicky McClure, aka Kate, has revealed she was certain she wasn’t going to be casted in the show after her audition.

McClure told GQ :“I remember my audition being a shocker. I hadn’t learned my lines, and I missed my mouth when I went to have a drink of water and it all went down my top”.

McClure was still cast as detective Kate Flemming – we guess her audition was one to remember...

Line of duty facts

5. A different EastEnders nickname?

DI Matthew ‘Dot’ Cottan originally held a nickname referencing another classic EastEnders star.

Fun fact: Craig Parkinson, who plays Matthew Cottan in the show, was supposed to be called Matthew ‘Babs’ Windsor, named after the soap-opera legend Barbra Windsor.

Which one do you prefer? Personally, we're surprised Matthew ‘Phil’ Mitchell wasn’t considered..

6. Plus sudden name changes

After the filming of Season One had wrapped, the production team made the decision to change the name of Lennie James, who plays Tony Gates, to, ahem, Tony Gates.

His original character name has never been revealed, nor has why the crew deemed it so important to change at the last minute. If you watch earlier episodes carefully, you can actually notice camera cuts when Gates’ name is said. Interesting...

Line of Duty facts

7. Real family members were in the show, too

Martin Compston’s real wife has appeared on the show, but unlike Jed Mercurio, you can actually spot her.

Tianna Chanel Flynn made her cameo as Tina Watts. Sadly, you only saw her photo on a dating profile – but this does mean that Martin’s dog is next to her in the appearence, too.

As well as Tianna making an appearance, Vicky McClure's nephew Kai makes a camea as the son of her character, DI Fleming. Now that is one cool aunt.

8. Rejection, rejection, rejection

This one's interesting. It's been widely reported that when writer Jed Mercurio first pitched his idea for Line of Duty to the BBC, he was met with rejection. He waited nine months before BBC 2 picked it up for one season.

Six seasons on and it is one of the biggest crime dramas the BBC has ever aired. Sounds kind of like J.K Rowling's Harry Potter story to us, which proves one thing, and one thing only - never give up on your dreams.

Tune in to the finale of Line of Duty this Sunday at 9pm. Reporting by Rosie Grant.

Ally Head
Health, Sustainability and Relationships Editor

Ally Head is Marie Claire UK's Health, Sustainability, and Relationships Editor, eight-time marathoner, and Boston Qualifying runner. Day-to-day, she works across site strategy, features, and e-commerce, reporting on the latest health updates, writing the must-read health and wellness content, and rounding up the genuinely sustainable and squat-proof gym leggings worth *adding to basket*. She regularly hosts panels and presents for things like the MC Sustainability Awards, has an Optimum Nutrition qualification, and saw nine million total impressions on the January 2023 Wellness Issue she oversaw, with health page views up 98% year on year, too. Follow Ally on Instagram for more or get in touch.