Jordan King Abdullah II has gone public with a royal rift with his half-brother Prince Hamzah and formalized the former crown prince's house arrest, calling him "erratic" in an unprecedented harshly worded public letter published Thursday.

He said in a public letter that he had approved measures to detain Prince Hamzah in his palace and restrict his communications and movements, citing his half brother’s "erratic behavior and aspirations."

"We will provide Hamzah with all that he requires to live a comfortable life, but he will not have the space he once abused to offend the nation, its institutions and his family, nor to undermine Jordan’s stability," the king said.

The announcement was the latest chapter in an ongoing Jordan's palace feud that saw the junior royal placed under a form of detention, and which has seen the internal disputes of the royal family spill into public in an unprecedented manner.

Abdullah and Hamzah are sons of King Hussein, who ruled Jordan for nearly a half-century before his death in 1999. Abdullah had appointed Hamzah as crown prince upon his succession but stripped him of the title in 2004.

The monarch had placed Hamzah under house arrest last April for his alleged plot to destabilize the Western-allied kingdom.