Jim Broadbent is to star in 'London Spy'.
The 'Harry Potter' actor has signed up to star in the five-part series created by 'Child 44' author Tom Rob Smith, which tells the story of a chance romance between two people from very different worlds.
Starring alongside Jim will be 'Restless' actress Charlotte Rampling, 'James Bond' star Ben Whishaw and newcomer Edward Holcroft.
Whishaw will star as Danny - a hedonistic and romantic party boy - who falls for Secret Intelligence Service employee Alex (Holcroft), who goes missing just as the pair begin to realise they are perfect for one another.
Tom said of the cast and director Jakob Verbruggen: "London Spy has gathered an exceptional cast and a visionary director. I couldn't be more excited, or proud."
The BBC's Head of Independent Drama, Polly Hill, added: "It's testament to Tom's wonderful scripts, that they have attracted such an incredible cast. Together with Jakob directing, this is an exciting team which promises to make London Spy an unmissable drama for BBC Two."
'London Spy' - which is produced by Guy Heeley and executive produced by Tom Rob Smith, Juliette Howell, Tim Bevan and Eric Fellner - is set to air on BBC Two in 2015 and will be made up of five hour-long episodes.

Reza Mahammad indulged in "grasshoppers, silk worms and water bugs" for his latest TV series.
The TV chef gorged on the food products while filming his latest Food Network cookery programme in Thailand, and while he admits he didn't always enjoy consuming the bugs, he insists they are healthier than chowing down on crisps.
He exclusively told BANG Showbiz: "Memories of eating insects was one which wasn't a great memory, but it certainly left an imprint on my mind! They breed insects over there for food.
"I ate grasshoppers, silk worms, water bugs; they were fried with lime and flavoured with lemon grass and a bit of chilli. Very crispy and crunchy! I kept saying I am not a celebrity, but get me out of here!
"Eating insects is better than eating crisps. They are highly nutritious. Some people say they are the future protein.
"I mean over there it is just normal. We wouldn't find eating them so disgusting if we were conditioned to them."
As well as filming in Thailand, the star also admitted he loves appearing as the chef on 'This Morning' because he has so much energy when he does a live demonstration.
He added: "I love it! It's just the energy there. It's always buzzing and when you are doing a live demo you are so charged. Everything happens on the spare of the moment and nothing is actually contrived."
Reza Spice Prince of Thailand, airs tonight (17.10.14) at 6:30pm on FOOD NETWORK UK
Freeview 41, freesat 149, Sky 248, Virgin 287 www.foodnetwork.co.uk

Chris Stark is worried he might have talked himself into wearing Scott Mills' crab outfit at the Radio 1 Teen Awards.
The Radio 1 star joked earlier this week that it would be funny if someone wore the crab costume, which his colleague donned during his 'Strictly Come Dancing' routine last weekend, at the event on Sunday (19.10.14) but he is now concerned he might be the unlucky guy as it's his first year at the event.
He exclusively told BANG Showbiz: "Scott performed on 'Strictly' last week dressed in a crab outfit so I stupidly said that might be a good idea.
"I don't know if in my one time at Wembley I should be dressed up in a crab suit. I'm not sure it's a good idea.
"But we will be having loads of fun there. Me and Scott will be hanging out backstage getting loads of photos, hanging out with all the artists and all the Teen Heroes of course, so it's going to be a really, really good day."
Chris can't wait to see the acts perform live at the Teen Awards, which will take place at the SSE Arena at London's Wembley, and admits he is fully prepared for the screaming when The Vamps take to the stage.
He added: "I've seen some of the guys when they've come into Radio 1 but I've not actually seen them live.
"I think seeing The Vamps live is going to be awesome. The noise when they go on is going to be insane. Labrinth always puts on a good show, I've seen him before and he just kills it every time."
BBC Radio 1's Teen Awards will be live on Radio 1 between 1pm-5:15pm on Sunday October 19. The whole event will be available to watch via a live stream on bbc.co.uk/radio1 and on BBC Red Button with TV highlights on CBBC from 5.30-7pm.

Tom Hardy, Ryan Gosling and Will Smith are close to signing on for new superhero movie 'Suicide Squad', according to reports. The trio of actors are in negotiations with Warner Bros. about lead roles in the DC Comics adventure as well as actress Margo...

Robert Downey Jr. took home a 30 foot letter 'A' from the set of 'The Avengers'.
The 49-year-old actor likes to collect props from his films as mementos to remind him of his movies, and he recently received a gigantic letter 'A' that he joked he wanted when he was filming the 2012 hit movie 'The Avengers'.
He told UK station BBC Radio 1: "On the last Avengers, there's this scene where there's this 'A' which is probably 30 feet tall, and I'm looking at it, and we're shooting in England, and I go 'I need that in my office in Venice'.
"About two weeks ago, a wheeler showed up, I'm like 'What the heck is this doing here?!' And they go, 'This is the 'A' you asked for.' And I go, 'They brought it?!' So now we have a massive Avengers 'A' that will be prominently placed."
Although he likes to collect props, Downey admits he was disappointed not to get an armoured suit from the set of any of the three 'Iron Man' films.
When asked if he still had the iconic costume, he said: "That's a tough commodity, I have some helmets!"
The Golden Globe winner was appearing on the station to promote his new movie 'The Judge' and explained that he enjoyed playing his character, Hank, as it is not a character which audiences would expect from him.
He added: "What I wanted to do was set it up an expectation that this is going to be something you're familiar with, me playing the kind of character you're familiar with, and over the course of three acts, just punch that idea in the stomach."

David Beckham has joined the fight against Ebola and has called on the world to help "collectively halt" the "ferocious" illness.
The 39-year-old star has urged people to act against the deadly disease - which has a 70 per cent death rate - to help those in Sierra Leone and other countries because he believes the shocking sickness can be stopped if everyone works together.
Speaking in a video for charity Unicef - for which he is a Goodwill Ambassador - he said: "Six years ago, I travelled to Sierra Leone with Unicef. I was inspired and honoured to have met so many amazing people and to see the beautiful country.
"While there I was lucky enough to get a glimpse into the lives of children in remote villages and the challenges they faced in a country then devastated by civil war.
"Today, the courageous people of Sierra Leone are facing an invisible enemy - a ferocious Ebola disease that's spreading fast across West Africa.
"The good news is that this disease can be avoided if you take the correct measures ... together we can collectively halt this disease in its tracks. Let's start now."
The former footballer - who has children Brooklyn, 15, Romeo, 12, Cruz, nine, and Harper, three, with wife Victoria Beckham - also sympathised with the victims of the terrible disease.
He added: "The images are heart-wrenching. As a father, I can't imagine what it must feel like, seeing your child suffer and feeling so helpless. But there is something you can do.
"Unicef is on the ground, working around the clock to protect children and families from this deadly virus. Please give Unicef the help it needs to tackle this crisis. We're in a race against time."
While David always seems to be working, a new study, commissioned for the launch of the new Samsung Galaxy Note 4 phone, has revealed the ex-England captain and his fashion designer wife have the best work/life balance out of any famous couple.
The pair beat off competition from the Duke and Duchess of Cambridge (12 per cent), Brad Pitt and Angelina Jolie (eight per cent) and Jay Z and Beyoncé Knowles (seven per cent).
What's more, respondents of the Samsung Galaxy Note 4 survey named David's career as the one they would like to have above any other male star.

Meryl Streep has paid tribute to her 'August: Osage County' co-star Misty Upham.
The 65-year-old star has spoken out following the news that a body found near a river in Seattle, Washington was confirmed to be that of the 32-year-old actress - who went missing nearly two weeks ago after admitting she was suicidal.
Meryl told The Hollywood Reporter: "So so sad to hear this news - all our thoughts are with her family and with her beautiful spirit."
Misty's co-star Melissa Leo, who she starred alongside in 'Frozen River', has also spoken of her sadness at hearing of the tragic death, saying: "Such a loss... so sad, so so sad."
Misty was last seen on October 5 near a relative's home in Auburn, Washington after returning to the Seattle area to help care for her father Charles Upham, who suffered a stroke last year.
After discovering his daughter had gone missing, Charles revealed that his daughter was upset and erratic and had stopped taking the medication for her anxiety and bipolar disorder.
Misty was a keen supporter of PETA, an animal rights organisation, who have also released a statement following her death.
Founder Ingrid E Newkirk said: "The world will be a colder place without Misty's warm heart, and she will be sorely missed at PETA. She was extremely kind and cared deeply about animals; constantly calling for protection for the bears suffering in roadside zoos on tribal land, a call we will carry forward in her honour. It's a tragedy whenever anyone dies before their time, but Misty Upham was a friend to us and to animals everywhere."
It is so far unclear what caused Misty's death, although Police Commander Steve Stocker said there was presently no evidence or information "to believe there is foul play".

Chloe Sevigny wants to start a family.
The 'Cosmopolitans' star recently moved to the upmarket New York City neighbourhood Park Slope in Brooklyn from the East Village and thinks it's the perfect place to raise kids.
She said: "Children would be nice at some point. I just bought a brownstone with the park across the street - it's the perfect setting for that storyline to play out. If you build it, they will come."
But the star says her future children won't have a conventional upbringing.
She said: "I'm as weird as you get. But that's OK."
The 39-year-old actress admits she wants to empower herself more and is a huge fan of actresses, like Mia Farrow, who speak their minds.
She added to Harper's Bazaar magazine: "I want to empower myself more, like Patti Smith or my friend Natasha Lyonne, not needing to bend to any ideals of beauty or fashion - being more female gangster.
"I also wish I weren't scared of taking a stand politically. It's heroic the way Mia Farrow is a public figure who speaks her mind on so many issues. I hope I'll become that. I mean, I'm in my apartment, sorting napkins. It's not very sexy."

Giuliana Rancic is considering adopting a baby.
The E! News anchor, who has son Duke, two, with husband Bill Rancic, was devastated when their surrogate, Delphine, miscarried their second child earlier this year, but still hopes to have a big family.
Asked if they would ever adopt, the 40-year-old star said: "Absolutely! We're not looking at it now, but if one day we're settled in the suburbs of Chicago, why not have a bunch of happy kids running around having a great life?"
The reality TV star hopes that Delphine will agree to carry another child for them in the future, as she is unable to get pregnant due to medication she is still on after successfully beating breast cancer in 2011.
She added to In Touch magazine: "Delphine had great pregnancies with her two sons and she had an amazing pregnancy with Duke. When she's ready [to try again,] we're 100 per cent ready.
"We'd like to wait until things slow down a bit, but if Delphine is willing to do it this year, that's great.
"I'd love a little girl."

Blake Lively may have only just announced her pregnancy, but her baby bump is already growing at a quick rate! The 27-year-old stunner is expecting a baby with 'Green Lantern' actor Ryan Reynolds and dazzled in a glittering gown at the Golden Heart Awa...

Josh Hutcherson shot to fame in the first two 'Hunger Games' films, and now the 22-year-old is set to become even more famous as he gears up to release the third film in the blockbuster series, 'The Hunger Games: Mockingjay - Part 1'. The hunky actor -...

Who could believe that Halle Berry is 48 years old?! The dashing actress looked jaw-droppingly gorgeous in a youthful white and blue frock at the Golden Heart Awards in New York. The Academy Award winner also showed off her on-trend bob which worked ex...