Britney Spears former employees have been spilling secrets about her poor parenting, insisting she often got drunk in front of her kids and hired nannies without paying attention to their childcare qualifications.

The Toxic singer is currently embroiled in a bitter court battle with her ex-husband Kevin Federline, who is seeking full custody of their two sons, Sean Preston, 23 months, and Jayden James, 11 months, after becoming concerned about Spears' parental skills.

And he's not the only one casting doubt on her fitness to be a mum - former employees have revealed she's a mental wreck too.

One tells Us Weekly, "She drinks in front of the kids. At first, the drinks would help her loosen up and not be so angry. But she'd inevitably drink too much and be out of it, at which point the nannies would take care of the kids."

Another source reveals, "She'll strip down in front of staff, nannies, whomever. She'll ask, 'Do I look sexy? Do I look pretty?' She's extremely insecure."

Others accuse the star of employing her workforce based on candidates' age and personality, rather than any formal qualifications or previous experience with children.

"She just cares about whether they're young and fun and like to drink and party. She hires people to be her friends."