Kevin Federline is reportedly unwilling to sign the final settlement agreements as part of his divorce from Britney Spears because he’s worried about her ability to look after their two children.

Echoing earlier reports that he’s worried about her mental health, a source close to Kevin told People magazine that under the current agreement the couple are supposed to share legal and physical custody of the boys but Kevin wants it reworded.

The source said: “Britney’s attorneys are anxious to see Kevin sign off on a divorce. But Kevin and his lawyer Mark Vincent Kaplan are dragging their heels out of concern over reports of Britney’s post-rehab partying.”

“[Kevin] wants to make sure that the divorce document makes it simple enough for [him] to downsize Britney’s access to her kids the next time her behavior troubles him.”

In related news, Britney has reportedly issued her mum with a legal letter, ordering her to stay away from the kids.

Britney travelled to Valencia, Califonia (where Lynne was supervising a photo shoot for Britney’s younger sister Jamie Lynn) yesterday afternoon to deliver the letter to her mum in person.

Sources claim Britney feels Lynne is currently unstable and the letter orders Lynne to stay away from Sean and Jayden if she’s taking any medication that would impair her ability to care or respond to the children.