Britney Spears has slammed her sister Jamie Lynn as "f***ing hateful" and a "selfish little brat" in a new post

Britney wrote: "You selfish little brat!!! Saying how weird and dumb it was that I had bought a house for Mamma !!! She was so proud and you told that interview girl that it was just weird ... LIKE I GUESS I WILL JUST WALK IN THESE HALLS ... Why did you say that ??? ."

Britney then went on to accuse Jamie Lynn of being "f****** hateful towards their mother - who divorced from their father Jamie in 2002 - as she continued her tirade.

She said: "My mouth was on the floor the way you talked back to Mamma when I came home ... Shocked out of my lined !!!!!! You were f****ng hateful to her and I know Mamma had been lazy with me but I'm sorry you deserved WAY MORE than a purse knocked at you by Mamma ... She should have WHIPPED YOUR A** ...Poor Mamma took it too just like I did in the end. She worshipped you too much I know but if you came out of my stomach, I would have popped the s--t out of your little a**." (sic)

The legendary performer has been embroiled in a feud with her sister - who is best known for appearing on children's television in the mid-2000s - in recent weeks, which came about when Jamie Lynn was promoting her new book 'Things I Should Have Said' and accused told Nightline that Britney had "locked [her] in a room with a knife", claim Britney has repeatedly denied.

She said: "And why watching your at length interview ... Really 2 HOURS or more ????? 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 ... OH BUT you don't want to keep talking about it because you don't want to HURT ANYBODY'S feelings ..."