Britney Spears/ Kevin Federline Custody Trial Will Go Forward, K-Fed's Lawyer Says

After a mediation session, lawyer Mark Vincent Kaplan says Brit's ex won't stop short of full custody.

On Thursday, Britney Spears, her father, Jamie, and her ex-husband, Kevin Federline, met at an undisclosed location for an all-day mediation session. Both sides wanted to see if they could hammer out an out-of-court agreement over the custody of the couple's two sons — Sean Preston and Jayden James — in advance of an August trial during which permanent custody of the young boys will ultimately be decided by a judge.

By the end of it, a compromise was not reached, meaning the August trial will proceed. Not long after Thursday's marathon mediation session, Federline attorney Mark Vincent Kaplan told E! Online that his client isn't about to let his guard down.

"Kevin is seeking to maintain the sole legal and physical custody that he presently has," Kaplan told the tabloid news site. "There's nothing magical about 50-50. There's nothing magical about 60-40. What's magical is that whatever order is in place, it's the order that best suits the best interest of the children."

In short, Federline wants his kids fulltime, cementing the temporary order now in place. "Kevin has had sole legal custody since January," Kaplan continued. "He wants that to become the permanent order at trial, and the visitation to be consistent with what the court expanded it to this week."

As it currently stands, Spears has been afforded overnight visitation with her sons, which will commence on Saturday night. She has also been awarded two daytime visits with the boys each week. And while Federline wants Spears to be a presence in his sons' lives, Kaplan said, he doesn't want to make concessions that would diminish his own right to be with his children.

"He wants to have an order ... that takes into account a certain stability and structure for the kids ... regardless of whose house they happen to be in at any given moment," Kaplan explained. "When the conservatorship was imposed, it brought a certain sense of structure and stability to an environment that seemed to be continually in flux. And in flux is not a description of what you want for a child's environment."

Although Thursday's mediation yielded no change in the couple's current custody arrangement, it did get both sides to the table, and it began a positive dialogue that Federline hopes will carry over into the August proceedings, his lawyer said.

"The mood was comfortable, positive, and it was a mood that was consistent with opening at least a great dialogue, which is necessary," Kaplan told E! Online. "The trial in August is going to determine two primary issues: custody and visitation, and attorneys' fees. ... If the existing arrangement was acceptable to both parties, we would have an agreement, and we wouldn't have to go to trial. But that didn't happen."