Rob Delaney has joined the cast of Jay Roach's untitled Roger Ailes movie.

The 'Deadpool 2' star is to take on the role of one of Megyn Kelly's producers in the motion picture, which will tell the story of the downfall of Ailes, the former Chairman and CEO of Fox News and Fox Television Stations, who will be played by John Lithgow, according to Deadline.

Malcolm McDowell is due to portray Rupert Murdoch in the film, which will focus on the point of view of the women who took on the toxic male culture of Fox News.

Murdoch, 87, was one of the CEO's strongest supporters, but ultimately made the decision to sack him.

Kelly - whose decision to go public with her story of abuse is seen as a monumental moment in the story - will be portrayed by Charlize Theron.

Nicole Kidman, Margot Robbie and Allison Janney have also signed up to the motion picture.

Kidman will play former Fox News anchor Gretchen Carlson - who sued Roger for harassment in July 2016 - with Robbie set to star as a fictional Fox News associate producer, and Janney is to take on the role of the chairman's defence lawyer Susan Estrich.

What's more, Ashley Greene will portray former 'Fox & Friends' host Abby Huntsman.

Delaney is best known for being the co-star and co-writer of hit TV show 'Catastrophe', and he recently made his movie breakout in 'Deadpool 2' alongside Ryan Reynolds, for which he didn't even have to audition.

He recently said: ''It so happened that Ryan Reynolds watched 'Catastrophe' and enjoyed it.

''And so he just called and said, 'Hey, do you want to be in the movie?' And I was like, 'Yeah, I'd like that'. And he was like, 'Do you want to know what you'll be doing?' and I said, 'I don't care'.''

He has also starred in zombie comedy 'Life After Beth' in 2014.