Miriam Margolyes ripped her former co-star, Steve Martin, calling him a “c–t” who was “rather horrid” to work with.

The actress — best known for her role as Professor Sprout in the “Harry Potter” film series — worked with Martin on the 1986 film “Little Shop of Horrors,” in which, Martin played a sadistic dentist and Margolyes was his assistant.

The scenes, which called for Martin, 78, to pretend to punch Margolyes, 82, in the face and knock her out were dreadful, the actress claims.

In her recently released book, “Oh Miriam,” she writes about being “hit all day by doors opening in my face” and “repeatedly punched, slapped and knocked down” by Martin.

“I didn’t enjoy it and I had a splitting headache at the end of the day,” she told news.com.au in a recent interview.

“He was incredibly unfriendly because he was a perfectionist,” she continued. “He was an artist and all he was interested in was getting the comic moment right, and he was correct to do that, but he should have included me.”

Margolyes added that she “would have included the person I was working with” but Martin “wasn’t interested in that.”

“I just thought he was rather horrid,” she bluntly surmised. “He was a c–t, that’s all I can tell you.”

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Despite the miserable filming experience, Margolyes confessed that she considers the “Only Murders in the Building” star to be “gifted.”

A rep for Martin did not immediately return our request for comment.

“When I saw the scene afterwards I thought, ‘Oh, he’s good, he really is good,’” she explained.

Margolyes also slammed Rolling Stones frontman Mick Jagger for being only interested in himself when she met him in 2001 while performing in “The Vagina Monologues” alongside Sophie Dahl, who Jagger was dating at the time.

“I just didn’t like him,” Margolyes said bluntly.

“He wasn’t interested in anybody else,” she explained. “He didn’t say ‘Good evening’ or ‘How’s the show going?’

“He thought he was important, and he is important, but important people should never think they’re important and should never show it if they think it. I just thought he was a tiresome old git.”

The actress recently delighted fans by posing naked for a series of cheeky photos for British Vogue’s Pride Issue.