Parenthood star Jason Ritter battled severe low self-esteem at the beginning of his acting career as he was constantly compared to his Tv icon father.

John Ritter shot to fame in 1970s classic U.S. shows Three's Company and The Love Boat, and went on to win over a new generation of fans in Felicity and King of the Hill.

His son decided to follow his dad into showbusiness and the 32 year old reveals he had a hard time trying to live up to his famous last name during auditions.

He tells, "When I was starting out, I would go in for auditions and I would get overwhelmed by my own insecurities. I would have my little jokes prepared, and the casting director would say, 'Before you start, I want to tell you that your dad was so funny' - and give him a nice compliment - and I would think, 'Oh, my God, you're about to see how far I am from him.'

"I wasn't just a guy in the room; I was humiliating my family."

John died of heart problems on 11 September, 2003, just two weeks before the premiere of his son's first big acting gig on Tv series Joan of Arcadia, and Jason admits he wishes his dad was around to see his work.

He adds, "He saw the pilot of the show. I did a play that both he and my mum came to see, and he saw me in episodes of Law & Order. He'd tell me he was proud of me. I do wish he'd been able to see all of the things since his death, but I also think somewhere maybe he is seeing them and all the things in the future."