Ashlee Simpson's dad has spoken out against criticism of his daughter following her disastrous performance on Saturday Night Live at the weekend.

Joe Simpson said he was "surprised" by the reaction her acid reflux-induced lipsync gaffe produced, but was confident that her credibility with youngsters wouldn't suffer.

"I was definitely surprised by the reaction because she didn't expose a boob, she wasn't doing drugs, she isn't anorexic and she didn't get married in Vegas," said Joe. "I don't think this will hurt her credibility with kids; they won't care."

Defending her use of the backing track, he continued: "Just like every other artist in America she has backing tracks ... so you don't have to hear her croaking through a song on national television. She never used them before, but you have to do what you have to do."