Britney Spears unleashes on 'selfish brat' Jamie Lynn again, dredges up rivalry with Christina Aguilera

Britney Spears is continuing a public tirade against her younger sister Jamie Lynn Spears, this time bringing up her age-old rivalry with Christina Aguilera as further ammunition. 

After initially deleting an Instagram rant in which she told her sibling: "I should have slapped you across your f**king face", the 'Toxic' singer has republished the message, as well as elaborating further on her feelings. 

The post largely responds to comments made by Jamie Lynn in a candid two-part interview with the podcast Call Her Daddy as part of a media run to promote her new memoir Things I Should Have Said

"You selfish little brat!" Britney tells Jamie Lynn in the message. "Saying how weird and dumb it was that I bought a house for mamma! She was so proud and you told that interview girl that it was just weird."

Referring to an allegation made by Jamie Lynn that Britney once shut her in a room while holding a knife, Britney wrote: "And the topic about the knife which is ironically the only lie you've ever told in your whole life." 

"Why is that conversation 20 min? And the most degrading to me," Britney continued. 

"Oh, but you don't want to keep talking about it because you don't want to hurt anybody's feelings... yet.

"You let it linger forever saying you felt unsafe with me and weird. F**k you Jamie Lynn!" 

Recalling a time when she returned home after her high-profile breakup with Justin Timberlake, Britney accused her sister of being "f**king hateful" to her mother as a 12-year-old. 

"My mouth was on the floor the way you talked back to mamma when I came home. Shocked out of my mind!" Britney wrote. 

Another incident detailed by Jamie Lynn in her forthcoming book accuses her mother of hitting her with a purse when an altercation turned physical. 

"You were f**king hateful to her and I know mamma had been lazy with me but I'm sorry you deserve WAY MORE than a purse knocked at you by mamma," Britney responded. 

"She should have WHIPPED YOUR ASS. Poor Mamma took it too, just like I did in the end. 

"She worshiped you too much I know but if you came out of my stomach I would have popped the shit out of your little ass." 

Finally, Britney shared her pain at feeling "shut out" by her sister when she returned home, inferring Jamie Lynn emulated Britney's pop rival Christina Aguilera as some kind of slight against her. 

"When I came home you and your little friends all thought I wasn't cool. You felt bad for me in the breakup, HELL NO you didn't! 

"You and your friends all dyed your hair like Christina Aguilera and you no longer would play with me anymore!" Britney wrote. 

"I never shut you out ever. I get it, you were 12 but you were f**king hateful to mamma being cool with your stupid dark hair. 

"You can paint it however you like, but dear child YOU shut me out when I needed you the most. Writing in your book saying I wasn't like your mom anymore. No, you hurt me," she concluded.