'Why Him?' screenwriter Ian Helfer has dubbed Bryan Cranston as "an unbelievable actor".

Bryan Cranston

Bryan Cranston

The 60-year-old actor stars as Ned in the upcoming comedy film, and Ian - who penned the script for project which also stars James Franco and Zoey Deutch - has nothing but praise for the former 'Breaking Bad' actor.

Speaking to Variety at the premiere in Los Angeles on Saturday night (17.12.16), Ian said: "Bryan is an unbelievable actor, an American treasure. He hasn't done comedy since 'Malcolm in the Middle' 20 years ago, and we were so thrilled that he wanted to do his first comedy with us."

'Why Him?' tells the story of an overprotective and loving father (Bryan) who goes to visit his daughter Stephanie (Zoey) at Stanford for the holiday season, only to be faced with her billionaire boyfriend Laird (James), who Ned believes to be wildly inappropriate for his young daughter. Things then get more complicated when Ned learns Laird is preparing to ask Stephanie for his hand in marriage.

Meanwhile, Ian also admitted he has been in a similar situation to the story, where his girlfriend's father was "not happy" to see him.

He said: "I'm not going to name names, but I briefly dated a very famous news man's daughter, and at the time I was a very unsuccessful actor in New York, and his daughter brought me to his house.

"That guy was so not happy to see me. I was the last thing he wanted to see. It was so funny because he was in everyone's living room at seven o'clock every night."

Elsewhere at the premiere, Megan Mullally - who plays Barb, Ned's wife and Stephanie's mother - gushed about her first "big part in a big movie."

She said: "Have you ever seen me in a big part in a big movie? No. This is my coming out party. This is a big deal for me; I was 57 years old, and I had never gotten a big part in a big movie."