Troubled pop star 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 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.