The popular double act, played by Dominic Brunt and Mark Charnock, will take centre stage in Paddy and Marlon's Big Night In, which is due for release in November.
Penned by Emmerdale scriptwriter Paul Roundell and directed by the soap's assistant producer Tony Hammond, the feature-length episode has been tipped to follow "the events of a not-so-quiet night in the country, and a morning after anybody would want to forget".
The story begins when Paddy and his girlfriend Rhona (Zoe Henry) are both desperate for a night out with their respective friends, leading to a debate over who should give up their plans and stay in with baby Leo.
Hinting at what happens next, an Emmerdale statement teased: "A fed-up Paddy and Marlon eventually lose out and the babysitting begins. Only this is 2011, and children are welcome in pubs nowadays, so one quick beer at The Woolpack won't matter - or will it?"
Hammond commented: "Dominic and Mark are exceptional actors with genius comedy timing. The Big Night In project is a brilliantly-written spinoff giving them even more scope to show their true comedic skills.
"Paul's script is laugh-out-loud funny and I know the audience will be crying, albeit with tears of laughter, as Paddy and Marlon get to grips with the morning after the night before!"
Along with Brunt, Charnock and Henry, Paddy and Marlon's Big Night In stars Sammy Winward (Katie Sugden), Natalie Anderson (Alicia Gallagher), Natalie J Robb (Moira Barton), Tony Audenshaw (Bob Hope) and Eden Taylor-Draper (Belle Dingle).
Filming for the spinoff will take place over the next two months, ahead of its release on November 14.
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