The BBC show, which doesn't yet have a title, focuses on characters called Nic and Jen, and their budding friendship.
Selin Hizli - who played Margaret in Grantchester and Connie in Land Girls - and This Country star Daisy May Cooper are best friends in real life. The duo have written the six-part series together, and will star in the lead roles.
The "character driven layered thriller", which will be made up of six 30 minute episodes, is described as "a twisted comedy about two mums, marital angst, maternal paranoia and a dead cat."
The BBC explains the plot as follows: "At the heart of this female fronted series is Nic (Daisy May Cooper) and Jen's budding friendship. Jen (Selin Hizli) arrives in town with her son Harry and disrupts Nic's lonely life with fun, laughter and booze. Nic's son Ollie also finds a new friend in Harry. Female friendship at its naughtiest and most intoxicating. That is until everything unravels."
The series is the first commission for Boffola Pictures, the production company setup by executive producer Kate Daughton and former BBC comedy commissioner Shane Allen, and is a co-production with Last Tango In Halifax producers Lookout Point. The episodes will be produced by Pippa Brown (The Other One) and directed by Jonny Campbell (Eric & Ernie). Jack Thorne (His Dark Materials, The Fades) will act as an executive producer on the project.
Daisy May Cooper says: "So excited to be writing this with my best friend and the funniest person I know on a subject that I think sums us up perfectly.... Toxic friendship."
Selin Hizli adds: "Everything about creating this show has been a dream come true. Jack Thorne, Lookout Point and Boffola Pictures have been incredible. I can't wait to bring this dark, funny world to life with Jonny Campbell and I'm so thrilled it has found its home at the BBC. Now I just have to put up with Daisy for a bit longer while we film it..."
Commissioner Kate Phillips says: "We are so proud that Daisy is continuing her relationship with the BBC to make this very special series with her best friend Selin. The scripts are golden and ooze pure comedy brilliance - viewers are going to devour this!"
Pippa Brown comments: "I feel like a prize winner getting to work with the absolute dream team of Daisy, Selin, Jack and Jonny on this incredible series. They've created an ambitious show that is totally unique in tone and genre and full of brilliant female talent - we can't wait for everyone to fall in love with Nic and Jen."
Jack Thorne notes: "Working with Selin and Daisy on this has been a joy. The way they've managed to balance joy and truth, funny and real, it's been a brilliant education for me as a writer. And the less said about that dead cat the better. Can't wait to get on set and see what magic they and Jonny make."
Jonathan Blyth, the director of comedy at BBC Studios which will distribute the series internationally, concludes: "We are delighted to be working with Daisy again on her next authored piece, and with Boffola and Lookout Point on their first comedy commission, to bring this brilliant comedy - thriller to a global audience."
The series will film in Bristol and around the West Country this autumn with further casting set to be announced in due course.