Sharon Horgan has opened up on the inspiration behind her powerful performance in Best Interests, a BBC One drama about a mother's fight to stop doctors switching off her disabled daughter's life-support machine.
The fictional four-part series, which has been penned by BAFTA-winning writer Jack Thorne (Help) tells the story of Marnie Lloyd (Niamh Moriarty) a 13-year-old who suffers from a rare form of Muscular Dystrophy.
When Marnie's condition deteriorates, the hospital caring for her suggest it's in the teenager's best interests that she be allowed to die, yet her mother Nicci Lloyd (Sharon Horgan) is desperate to keep her alive.
"I just completely took Nicci's position," says Horgan. "It was the only way to do it. It's just in her blood, it's in her bones."
The Catastrophe and Bad Sisters star went on to admit that she went through something similar 'although in a much smaller way' when her own daughter was a baby.
"My daughter is 19 now, but when she was really young, she had meningitis," she explains. "There was a lot of time spent in hospitals on the ICU, so I'd been in the PICU, where a lot of the script and a lot of this story is set.
"When my daughter was first taken into hospital, my reaction was, ‘Whatever happens, save her life. I don't care what you have to do. I don't care if she loses limbs, I don't care. Do whatever you have to do just keep her alive.’ I think that's Nicci's position throughout and I could just completely relate to it."
Horgan stars alongside Michael Sheen (Good Omens) who plays her husband Andrew in the four-part series and says she was determined to take on the role, despite being exhausted from a 10-month shoot for Bad Sisters season 1.
"I was in the middle of filming Bad Sisters which was a good 10-month extremely grueling schedule that was completely all-encompassing," she explains.
"I didn’t want to start something else as soon as it finished but my agent said, ‘You know, do you want to have a look at this?’ I went, ‘Well, no.’ When she said it was Jack Thorne, someone I've been wanting to work with for a while, I read it and it just messed me up.
"They always say that if you could imagine someone else doing it, and you're okay with that, then just let it go. I suppose I couldn’t: I wasn't okay with someone else doing it. You always look for a reason for doing anything you do. But sometimes entertainment can feel a bit frivolous, and you sort of end up feeling like, what's the point? Like, what's the point of me? What's it all about? But this is really great, thought-provoking stuff, the sort of stuff that doesn't come along that often."
Co-writer and star of C4 comedy Catastrophe and the creator of award-winning sitcom Motherland, Horgan isn't famed for her dramatic roles but says that despite the subject matter she and the rest of the cast had good fun during filming.
"This is the most serious thing I've ever done," she says. "I'm used to doing completely different kinds of things. You don't expect something like this to be fun, but it was because it was so intense during filming that we just had to release something when we weren't filming. I can't explain it, but it was actually a real laugh."
Best Interests premieres on BBC One and BBC iPlayer on Monday, June 12