Britney Spears could lose custody of her two children as early as Monday morning. LA attorney Gloria Allred is bringing a "secret" witness to court on Monday for the custody battle between Spears and ex-husband Kevin Federline. Allred filed a signed declaration from the witness, described only as a man who's had close observation of Spears's behavior with her kids. The judge in the closed-hearing case is in possession of the declaration does not have to rule on it; he can simply read it and enter it into the case's existing papers. The only way the witness would testify is under cross examination. In other words, the declaration has already served as testimony. It would only be if Spears's side decided to question that the witness would be asked to speak. The witness will be in court with Allread at 8:30 a.m., and could blow the popstar's chances of keeping Sean Preston and Jayden James. Allred has kept the witness's identity a "secret" so as not to start a publicity war. But when the declaration was filed on Friday, Spears and her attorney Laura Wasser would have learned his name. "You may recognize him as we walk into court," Allred says of the witness. "But maybe not. He is not famous. He's just someone who's concerned about the kids."