Britney Spears goes on ANOTHER rant against sister Jamie Lynn Spears - Daily Mail

Britney Spears has posted yet another blistering attack on Jamie Lynn Spears, calling her a 'selfish brat,' despite sending a cease-and-desist letter ordering her younger sister to stop talking about her.

After initially deleting her Tuesday post - whereby Britney, 40, said she should have 'slapped' her sister Jamie Lynn, 30, and mother Lynne Spears - she has now re-posted an even longer version with new details on Wednesday.   .

In her extended post, Britney calls Jamie Lynn a 'selfish brat' who once refused to play with her after she had split up with ex-boyfriend Justin Timberlake. .

Toxic: Britney Spears has posted yet another blistering attack on Jamie Lynn Spears, calling her a 'selfish brat,' despite sending a cease-and-desist letter ordering her younger sister to stop talking about her.

Longer version of events: Britney Spears goes on ANOTHER foul-mouthed rant against sister Jamie Lynn on Wednesday...

Britney Spears (pictured) yesterday sent a cease-and-desist letter ordering her sister, Jamie Lynn Spears, to stop talking about her.

Jamie Lynn is currently on a promotional tour for her new book 'Things I Should Have Said', which Britney's legal counsel said contains 'misleading and outrageous claims' about Britney.

Lawyer Mathew Rosengart has written a stinging letter to Jamie Lynn, demanding that she 'cease and desist from referencing Britney derogatorily' and threatening 'all appropriate legal action' should the actress not comply.

Lawyer Mathew Rosengart wrote a stinging letter to Jamie Lynn, demanding that she 'cease and desist from referencing Britney derogatorily' and threatening 'all appropriate legal action' should the actress not comply. .

The letter comes as Britney hit out against Jamie Lynn and her mother Lynne in a fiery Instagram post in which she said she should have slapped them both 'across their f***ing faces'.

Lawyer Mathew Rosengart has written a stinging letter to Jamie Lynn, demanding that she 'cease and desist from referencing Britney derogatorily' and threatening 'all appropriate legal action' should the actress not comply

Pictured: the cover of Jamie Lynn Spears' memoir, entitled Things I Should Have Said

News of the letter comes as Britney continues to hit out at her sister and mother in a wild Instagram post in which she said she should have 'slapped' her family members 'across your f***ing faces.' 

In her extended post, Britney implies Jamie Lynn had gotten a cushier upbringing and a starring role on TV when she was just a child

Jamie Lynn is said to receive death threats 'every time Britney posts' according to the source, and has asked her to stop with no avail