The low-budget comedy will explore the relationships of seven British couples during one afternoon, Daily Variety reported Monday.
Other castmembers include Hugh Bonneville, Andrew Lincoln, Gina McKee, Eileen Atkins, Benjamin Whitrow, Douglas Hodge, Mark Strong, Polly Walker, Adrian Lester, Holly Aird, Tom Hardy and Catherine Tate.
Variety said Blum established his own production firm, Tin Pan Films, in June and raised the funding for his first full-length film in just six weeks.
Filming is expected to take three weeks.
2014: The Year in Music [PHOTOS]