Britney Spears has called her baby sister Jamie Lynn Spears “scum” again in a brand new rant.

Jamie Lynn has been boasting about her new book being a best seller.

“I wish you would take a lie detector test so all these masses of people see you’re lying through your teeth about me !!!!” Britney wrote on Instagram. “I wish the almighty, Lord would could come down and show this whole world that you’re lying and making money off of me !!!! You are scum, Jamie Lynn.”