The 40-year-old daughter of Elvis Presley said the story, which was widely republished worldwide, forced her to confirm she is expecting a baby.
Her UK laywer Simon Smith said claims that she had an âunhealthy appetiteâ and is âgrowing like her dadâ had left the star âdeeply upset and offendedâ.
Presley called the press âdisgustingâ on her MySpace page.
The singer, who is issuing the libel claim against the Daily Mailâs publishers, Associated Newspapers, at the High Court in London, also explained why she was forced into disclosing her pregnancy.
âI have had to show my cards and announce under the gun and under vicious personal attack that I am in fact pregnant,â she wrote.
â**Badgering and harassingâ**
The announcement comes days after photos of Presley eating lunch in Los Angeles emerged in some newspapers poking fun at her weight gain.
âOnce they got a glimpse of my expanding physique a few days ago, they have been like a pack of coyotes circling their prey whilst eerily howling with delight,â said Presley.
She claimed publications in London, New York and Chicago wrote âfalse defamatory degrading storiesâ about why she could be putting on weight.
âNow that things are confirmed, hopefully they can stop all of the harassment and I can stop dodging the continuous bullets,â she said.
Addressing other women she added: âYou know if you were pregnant and you felt you were expanding uncontrollably by the moment as a result, and the worldwide media started badgering and harassing you for it, plastering you everywhere in an unflattering light, you would be mortified as well.â
Speaking to the Associated Press, her spokeswoman Cindy Guagenti said some of the stories had gone too far.
âItâs like, âsheâs gonna die like her fatherâ, âher and her mom are in a fight because of her weightâ - thatâs not true at all. Itâs just awful stuff,â she said.
Presley said both she and husband, music producer Michael Lockwood, were âincredibly happyâ about their news.
She already has an 18-year-old daughter and a 15-year-old son from her first marriage to musician to Danny Keough.
She briefly married Michael Jackson in 1994 and then actor Nicolas Cage.