British comic Catherine Tate's foul-mouthed grandmother character, whose cursing has kept audiences chucking for 15 years, is to star in a feature-length film called "This Nan's Life", media reported at Cannes on Monday.
It will be directed by Josie Rourke, of London's Donmar Warehouse theatre, whose first feature "Mary Queen of Scots" starring Saoirse Ronan was warmly received last year.
Nan was created as a character on the "The Catherine Tate Show", a hit comedy sketch series which ran on the BBC from 2004 to 2009.
The movie will focus on how Nan became who she is and will also feature her grandson Jamie, played by regular co-star Mathew Horne, Screen reported.
Tate wrote the screenplay with fellow actor and comedian Brett Goldstein, who also worked with her on several Nan specials.
"A belligerent old-age pensioner... who tends not to like the world," Tate said the character emerged from an experience at drama school when she was sent to entertain a group of old people at a nursing home.
"We had to stand up in front of them and sing," she said, recalling how one old lady who was less than impressed.
"At the end of it, she went: 'Is she going to stand in front of that f**king telly all day?'"