The play, a two-hander titled Tree, runs from 11 to 21 September 2013.
Key tweeted earlier today: "I'm in Daniel Kitson's new play. It's called Tree. I'm playing a man. I cannot wait."
The Royal Exchange website says, "The show is still being written and so information is currently pretty scarce. There is currently no running time, no marketing copy, no programme image."
Daniel Kitson emailed subscribers with the following overview of Tree: "It's early evening. It's mid autumn. It's starting to get dark. And on a quiet residential street somewhere in England, a man with a picnic basket, arrives at a tree. A new show about dissent, commitment, two people and a tree."
Since winning the Comedy Award (then called the Perrier) in 2002 Kitson has written and performed a number of storytelling shows, including the Fringe First winning The Interminable Suicide of Gregory Church and 66a Church Road.
Tim Key won the Comedy Award in 2009 for this show The Slutcracker. His acting credits include Tom Basden's The Party on stage, and Alan Partridge: Alpha Papa on screen.