Britney SpearsBritney Spears is reportedly so worried that estranged husband Kevin Federline will get permanent full custody of their two sons that she’s checked herself back into rehab for the third time in just over a week.

Kevin had requested an emergency court hearing for today to discuss custody of 17 month old Sean and 5 month old Jayden but it has been cancelled after Britney returned to Promises Center in Malibu this morning. Sources are claiming that he’s threatened that he will seek unquestioned full legal and physical custody of the boys if Britney leaves before completing a full rehab programme, lasting between 30 and 45 days.

Britney left the facility yesterday morning less than 24 hours after checking in on Tuesday. She was spotted visiting a lawyer’s office then went to Kevin’s home in the San Fernando Valley.

Onlooking paparazzi report that she repeatedly buzzed the intercom but didn’t get an answer and took out her frustration on the photographers by hitting their car with an umbrella and shouting at them.

Britney has reportedly drafted in her mum, Lynne Spears, to strengthen her custody case and the children are being looked after by a combination of Lynne, Kevin and Kevin’s mother.

In related news, the National Enquirer is reporting that the showdown Britney had with Kevin on Friday that spurred her into shaving her head also caused her to attempt to kill herself twice on Friday night - hence her visit to Cedars Senai Medical Center on Friday night.

A source told the publication: “Britney was crying and said she would kill herself if she lost the boys.”

“During the night, she escaped and tried to walk into oncoming traffic. Britney said she wanted to kill herself. She later grabbed a bottle of Xanax and said she’d take the whole bottle - she didn’t care what happened to her.”

“Britney’s family are terrified she’ll end up like Anna Nicole Smith - on a cold slab in a morgue, leaving her young sons without a mother. She’s on the same self-destructive path.”