Olivia Colman and Julian Barratt are to play a husband and wife in a "deliciously dark" comedy about a "brilliantly peculiar" family.

Channel 4 confirmed the commission of the six-part series Flowers - about the dysfunctional and eccentric Flowers family - at the Edinburgh International Television Festival.

Broadchurch and Peep Show actress Colman plays music teacher Deborah and The Mighty Boosh star Barratt plays Maurice, an author of twisted children's books. The pair are a husband and wife who are barely together but yet to divorce.

As Maurice fights inner demons and dark secrets, Deborah tries to keep the family together at all costs and becomes increasingly suspicious that Maurice is in a secret homosexual relationship with his Japanese illustrator Shun, played by Will Sharpe.

They live in a creaky, messy, crumbling old house with Maurice's mother Hattie, played by Leila Hoffman, and their 25-year-old twins - Amy, played by Sophia di Martino, and Donald, played by Daniel Rigby.

Swinging from the magical to the mundane to the downright mad, the eccentric Flowers and their often self-inflicted crises, are surrounded by even stranger neighbours who become the agents of yet more everyday chaos and disaster, Channel 4 said.

It is written and directed by Bafta-nominated writer and director Sharpe, and is produced by Kudos, which has worked on Utopia, Humans, Broadchurch, and The Hour.

Writer Sharpe said: "I feel very lucky to be making this show with Kudos and Channel 4.

"They have been unfailingly supportive and have pushed me to make bold decisions on a show that seeks both to celebrate and to challenge the traditional sitcom format.

"This is a comedy about people who are struggling and the situations that can arise when you refuse to admit that there are problems.

"Our aim is not to make light of the darkness, but to find the light within it."

Channel 4's deputy head of comedy, Nerys Evans, said: "Flowers is the kind of deliciously dark comedy we love at Channel 4.

"The word dysfunctional doesn't even come close to describing quite how brilliantly peculiar the Flowers family are.

"Will Sharpe's genius coupled with an amazing cast has led us to an unbelievably original piece and we are delighted to have it on the channel."

Naomi de Pear, who developed the series and will produce for Kudos, said: "Flowers has an other-worldly quality to it, even though it's about real characters and real emotions.

"I couldn't be happier that Will brought this dark, hilarious and emotional vision through our doors and it's been such a joy to develop and see it come to life with our extraordinary cast."

Flowers will be made in association with NBCU's new comedy-focused subscription VOD platform.

It was commissioned by Phil Clarke, Channel 4's head of comedy, and is due to be screened in 2016.