Rome star Kenneth Cranham will play former Labour prime minister Harold Wilson in a new BBC4 docudrama written by journalist and author Francis Wheen.
Celia Imrie and Gina McKee will co-star in The Lavender List, named after Wilson's notorious resignation honours list written by his personal secretary, Marcia Williams.
Cranham, who became a household name 20 years ago thanks to his title role in ITV's Shine On Harvey Moon, plays one of the leads in BBC2's swords and sandals epic. He has also appeared on the big screen in Layer Cake and Gangster No 1.
Forsyte Saga star McKee will play Williams, while Imrie, a costume drama veteran and long-time collaborator with Victoria Wood, will play Wilson's wife, Mary.
"I'm absolutely thrilled that Francis Wheen has penned such an extraordinary story about extraordinary people for BBC4," said the channel's controller, Janice Hadlow.
The cast also includes Neil Dudgeon as Wilson's press secretary Joe Haines, and Dominic Rowan as policy chief Bernard Donoughue.
Alison Willett is to produce The Lavender List, which will be broadcast on BBC4 next year.
The BBC said the drama would reveal "the aberrant behaviour of the last Wilson government, and exposes its rotten core: the PM's intense and warped relationship with Williams and the unbelievable control and power she had over Wilson".
Wheen, a former columnist for the Guardian, is also deputy editor of Private Eye and a regular panellist on Radio 4's The News Quiz.
A prolific author, his latest book is How Mumbo Jumbo Conquered the World: A Short History of Modern Delusions.
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