Liar’s Joanne Froggatt agonised over playing another rape storyline after Downton Abbey

Now Froggatt stars alongside Ioan Gruffudd in a new psychological drama from The Missing creators Jack and Harry Williams. At the heart of Liar is a rape accusation by Froggatt's character Laura Nielson against her date Andrew Earlham (Ioan Gruffudd) – but viewers won't know who to believe.

So did Froggatt have any reservations about signing up for the role?

"Yeah, absolutely," she told the press at a preview screening in London. "It was a thought process. I did sort of read it and go, 'Oh, if only it was a different subject matter.'"

"Obviously when I started Downton, my character was lovely and she wasn't going through a traumatic time and it was sort of a love story. So I didn't know I was going to be given that storyline. I still stand by that storyline completely and utterly, and the show for doing it.

"But then I sort of said to myself, this character is so completely different in every way."

And in many ways, the roles are miles apart. For one thing, in Downton we witnessed Anna's rape so we knew beyond a doubt that it had happened. By contrast, in Liar viewers will spend the first few episodes in the dark before finding out who is telling the truth about what happened that night. Along the way, Laura will make some frustrating decisions.

"This character doesn't make the right decisions and this character is flawed, Laura is flawed," said Froggatt. "She does things that I sort of had to go, 'Why, why? No that's just not a good thing to do!'"

"No matter which way the story goes, I just think it's a great thing to be a part of something that can open up conversation about a sensitive subject matter."

And playing a rape victim twice? "I've played a murderer three times, so you kind of go, 'You know actually it's okay,'" Froggatt added. "I'm an actress, I've been doing it for 20 years, sometimes subject matters are going to come around again."

Liar airs on ITV on Monday 11th September at 9pm