The divorce has been official for a few weeks, but that hasn't stopped Kevin Federline from keeping the battle going. Britney Spears' ex-husband is aggressively seeking sole custody of their two sons, 23-month-old Sean Preston and 11-month-old Jayden James.

E! Online has reported that Federline's attorney Mark Kaplan has been sending subpoenas to several people in Spears' recent history over the past week. On Saturday, August 18, Kaplan served an administrative executive at Promises Treatment Center in Malibu, California, where the pop princess spent four weeks in rehab this year. Federline's side has also reportedly targeted her close friend Alli Sims, former Spears assistant Shannon Funk, and her bodyguard Daimon Shippen.

All of these individuals are expected to provide testimony regarding Spears' parenting capabilities and her partying habits. After her separation from Federline late last year, the singer had an emotional breakdown full of bizarre behavior that became a field day for tabloid and mainstream media alike. Even before that, she had been a subject of controversy regarding her parenting skills.

Kaplan stated in a court hearing recently that the children are more "isolated from risks" with Federline than with Spears. "This has nothing to do with money. It never has," the attorney said.

On top of that, Spears' own attorney wants to quit, according to TMZ. The entertainment website reported yesterday that lawyer Laura Wasser is trying to leave the case and convince Spears to find another lawyer for her custody case. The singer, however, reportedly has come to rely so heavily on Wasser that she is resisting any other alternative.

A source close to Federline told E! this month that he has considered serving Spears' mother Lynne with a subpoena as well if he deems it necessary. "[Federline] knows the trouble it will cause, so he's trying to avoid it," the source said. "But if he has to, if it means the difference between getting his kids or not, he'll do whatever it takes." Spears' parents have been allegedly supporting Federline's side, according to reports.

"Britney really resents her parents for backing Kevin. And if Kevin drags them all into court, it's going to get so ugly," the source added.

It doesn't look like this is going to end well for those involved -- especially for the children. No matter how good your intentions are in protecting your children from your ex, an overt battle can be very traumatic for them in many ways, even at such a young age. Click here for an article on how to lessen your children’s divorce-related trauma.