Amanda Bynes has branded model Chrissy Teigen "ugly" in a Twitter tirade.

The troubled actress launched a venomous attack against the Sports Illustrated model and claimed she is "far prettier" than Chrissy in her tweets after Chrissy questioned her mental state in light of her recent woes. Chrissy, 27, tweeted in the early hours of Wednesday morning, "The fact that Amanda Bynes has any 'support' to retweet is really unsettling."

She's the Man star Amanda hit back with a long message, calling Chrissy an "ugly model." She wrote, "Ur not a pretty model compared to me. I signed to Ford models @ age 13. I don't look up to u beauty wise. I'm far prettier than u! I'm offended that you're saying I have a mental illness when I show no sign of it, but thankfully not one man that wants me wants you and you are an old ugly model compared to me! You look 45! You're not pretty so I'm not intimidated by you! I think you're jealous that you're just an ugly model whos career is uninspiring! I don't respect you! You're no beauty queen! I'm a beauty queen! (sic)"

Chrissy - who is engaged to singer John Legend - refused to bite back, tweeting, "Nope. Not going to indulge. Wish the best for her, truly."

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