Robin Wright demanded a pay increase to match her
co-star Kevin Spacey's salary - and the threat worked.
The 50-year-old actress threatened to "go public" with the discrepancy if bosses on the Netflix programme didn't recognise her contribution as First Lady and Vice Presidential candidate Claire Underwood was just as valuable as that of her on-screen spouse, who plays President Frank Underwood.
Wright has appeared in all 52 episodes of the show, as well as directing some of the series and serving as executive producer on the recent fourth season of the political drama.
Speaking at an event at the Rockefeller Centre in New York, she said: "I was like, 'I want to be paid the same as Kevin'.
"It was the perfect paradigm. There are very few films or TV shows where the male, the patriarch, and the matriarch are equal. And they are in House of Cards.
"I was looking at statistics and Claire Underwood's character was more popular than [Frank's] for a period of time. So I capitalised on it. I was like, 'You better pay me or I'm going to go public' And they did."
Wright - who has children Dylan, 25, and Hopper, 22, with ex-husband Sean Penn - took time out from her film career to raise her family and admits it impacted both her earnings and her professional standing.
She said: "Because I wasn't working full time, I wasn't building my salary bracket. If you don't build that ... with notoriety and presence, you're not in the game anymore. You become a B-list actor. You're not box office material.
"You don't hold the value you would have held if you had done four movies a year like Nicole Kidman and Cate Blanchett did during the time I was raising my kids. Now I'm kind of on a comeback at 50 years old."
Last year, financial bible Forbes reported Wright had made US$5.5 million (NZ$8.2m) for her work on House of Cards, which worked out to around US$420,000 (NZ$624,000) an episode.
In 2014, Spacey, 56, was said to be making US$500,000 (NZ$743,000) per episode ahead of season three debuting, but it was predicted it could rise to US$1 million (NZ$1.49m).
Gender pay gaps in Hollywood have become an increasingly touchy subject of late, after Hunger Games actress Jennifer Lawrence penned an essay in which she blamed herself for not fighting harder to get a better pay packet in American Hustle.
"When the Sony hack happened and I found out how much less I was being paid ... I didn't get mad at Sony. I got mad at myself," she wrote.
Last year, British actress Sienna Miller walked away from a role in a Broadway play after learning she was to receive just half of the salary of her male co-star.
The American Sniper star revealed she had been in talks to return to the New York stage, but pulled out of the production upon discovering the huge pay disparity.
"It was a play with just two of us on stage and I was offered less than half of what he was going to be paid. If it was two men, it wouldn't probably happen. Sad, but I walked away," she told Britain's The Sunday Mirror.
- Bang! Showbiz