He said Dame Jilly was heavily involved in the production.
“To see the joy on her face when she came to visit with all the amazing actors and crew, and she was really, really supportive.”
The second season is set in 1987 with the backdrop of a general election.
Holman said the costumes were crucial to making the era feel authentic, and that he dipped into his own collection of original Vogue magazines to begin researching the decade.
Many costumes were made especially for the cast while others were purchased from vintage stores.
“I’m always searching for vintage jewellery,” he said.
“In fact, Splott market [in Cardiff] was the place to go, and one of the stallholders was saying, ‘why are you buying all this?’.”
Holman said he was also guided by Dame Jilly when creating different looks for her characters.