Sinead O'Connor threatens to sue Miley Cyrus if she fails to apologize

Sinead O'Connor has written a third letter to Miley Cyrus accusing her of damaging her career and demanding an apology as well as urging her to "cease behaving in an anti-female capacity".

The 46-year old Irish singer-songwriter has accused the 20-year old daughter of country singer Billy Ray Cyrus of deliberately trying to hurt and trouble her personally and professionally, and even threatened her with legal proceedings if she refused to publicly apologize to Amanda Bynes and all mental health sufferers as well, the Mirror reported

'The Lion and the Cobra' artist added that "it is not acceptable to mock any person for having suffered" and predicted that the 'Stay' singer will also end up in a psych ward or a rehab soon.

The former fiance of Liam Hemsworth had posted a message on Twitter mocking O'Conner's mental illness, by comparing the 'War' singer to the 'She's the Man' actress.

The 'Sacrifice' singer had written her first letter after Cyrus revealed that her near naked 'Wrecking Ball' video was inspired by her 'Nothing Compares 2 U' hit.