Fighting reports that she's pregnant and having marital problems with husband Kevin Federline, Britney Spears on Wednesday (March 30) called those stories "false" and the reporters who write them "liars."

On her Web site, Spears wrote an open letter to Us Weekly, Star and what she called other "desperate magazines," saying that the scrutiny is not only unfair but hypocritical, since the tabloids don't fess up to their own imperfections. She addressed the letter to "false tabloids" and said their coverage showed they obviously don't care about reporting the truth.

Star and Us Weekly have reported that the pop star is three months along, claiming that a recent doctor visit was to get a sonogram. They've also noted that Spears hasn't been spotted drinking or smoking, and both have run pictures that appear to show Spears has gained weight in her breasts and abdominal area.

That weight gain, however, could be attributed to her junk food diet and a relaxing of her previously strenuous exercise regime. Spears joked in Allure's April cover story that the extra pounds are the "honeymoon aftereffect" of "just lounging around and eating and lying out" during the early days of her marriage to Federline. That marriage, Star and Us Weekly report, is on the rocks because Federline isn't enthused about adding another child to the mix (he already has two children with former girlfriend Shar Jackson, 2-year-old Kori and 8-month-old Kaleb).

"Your employees are a reflection of your magazine," Spears wrote in her letter. "I'm really concerned about the people you hire to work at your companies. I'd like them to ask themselves the question 'What am I lying to myself about?' Is it that you are 50 pounds overweight? Is it that your children aren't making wise decisions? Or is it maybe that your husband or boyfriend is cheating on you? Until you face what is going on in your life, I guess you'll remain a false tabloid."

Spears' opinion, spokesperson Leslie Sloane Zelnick said, is "shared by many."

Both Star and Us Weekly issued statements Wednesday insisting that they stand by their reporting. Us Weekly elaborated: "Unlike other magazines that pay for access to Britney, the writers at Us Weekly have high journalistic standards and do their own researching and reporting for all stories. Our coverage of Britney has proven to be accurate."

Spears has expressed much dissatisfaction in the media's coverage of her lately, complaining that Allure's April cover story on her focused too much on her personal life, and lambasting Us Weekly for printing her honeymoon photos (see "The Honeymoon Is All Over: Britney PO'd Over Leaked Photos"). She has vowed not to reveal as much private information in the future (see "Britney Spears Promises To Shut Up About Her Personal Life").