Lisa Marie Presley is frustrated and angry that her previously unannounced pregnancy has been turned into a reason of mockery at her expanding waistline and wishes to sue British newspaper the Daily Mail.

The daughter of music legend Elvis Presley, Lisa Marie Presley, is hurt that what was meant as a time of happiness for herself and her family turned into a situation where she had to defend herself against “vicious personal attack.”

Amid growing reports regarding her changing silhouette, Presley, 40, chose to reveal the real reason behind this – but she was not happy with the situation.

“After being the target all week of slanderous and degrading stories, horribly manipulated pictures and articles in the media, I have had to show my cards and announce under the gun and under vicious personal attack that I am in fact pregnant,” Presley wrote last Thursday on her MySpace Celebrity blog.

In the message titled “Confirmation under the gun,” she writes that she hopes all the tabloids will now back off and let her be. “It is unfortunate that I couldn't have announced something that is this much of a blessing and that has made us so incredibly happy under better circumstances,” the message continues.

Presley also found it within herself to apologize for the “contemptuous tone” of her writing and confessed that she had been “mortified” to see unflattering photos of herself.

Presley’s mortification also gives way to some litigation, People magazine is reporting. An article in British newspaper the Daily Mail seems to have angered her more than others, as it discusses her “unhealthy appetite” and how she “has gained weight like her father Elvis.”

Her lawyer, Simon Smith, issued a press release announcing the libel claim, saying: “My client is deeply upset and offended by this article, especially as it was widely published just as she and her family were meant to be celebrating her happy news.”

This is the first child for the singer-songwriter and her husband, guitarist and music producer Michael Lockwood, 46; they married in Japan in January 2006. Presley has two children, daughter Riley, 18, and son Benjamin, 15, with ex-husband Danny Keough.