The six-part workplace comedy - previously known as Cut - will air later this spring.
Fresh Meat's Ashton stars as the mercurial Katherine, who is recently divorced and troubled by secrets in her past.
Relocating from London to Northampton to join the Immigration Pathway department, Katherine discovers that her problems may only just have begun.
Sacha Dhawan, Tom Weston Jones, Jo Hartley, Sophie Rundle, Samuel Barnett and Anastasia Hille will also star in Not Safe for Work.
The series has been created and written by DC Moore, a former star of Channel 4's new talent strand Coming Up.
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