The IFP has accused King Misuzulu kaZwelithini's spokesperson, Prince Africa Zulu, of destroying the office of the Zulu monarch.
In a long statement, the party has challenged the prince to provide evidence backing up his allegations that the IFP and Prince Mangosuthu Buthelezi are plotting to dethrone the king, or face legal action.
"With the re-emergence of Prince Africa in His Majesty's Office after previously being fired for his questionable and crude behaviour, he now presents the biggest threat to the unity and stability of the AmaZulu nation," the statement read.
It further said Prince Africa only has one objective: destroying the credibility of the Office of His Majesty the King and dragging it into the political arena.
IFP spokesperson Mkhuleko Hlengwa said Prince Africa's conduct is not only unbecoming, but an absolute disgrace for someone tasked with upholding the decorum, dignity, and image of His Majesty's Office.
Prince Africa claimed last week that the IFP and Buthelezi are behind the infighting taking place in the Zulu royal family.
He also alleged that Buthelezi wants to dethrone Misuzulu and form a special committee for the throne.
Hlengwa said the conduct of the king's spokesperson is hardly surprising.
He claimed that Prince Africa is known for his personal struggles and unethical behaviour, and is using his role as his majesty's PA to execute the work of those who pay him.
Hlengwa highlighted the role of IFP MP Liezel van der Merwe in assisting Buthelezi with media statements in his capacity as traditional prime minister to the Zulu king.
He said Van der Merwe is acting voluntarily as Buthelezi's personal assistant since no salary is allocated for the traditional prime minister, or for his staff.
The Zulu royal family faction that supports Prince Simakade as the next king appears to be reacting with glee to the public infighting.
On the ANC WhatsApp group, Princess Zandile and Princess Mbali suggested that Prince Africa seemed to be "on drugs", judging from his behaviour and the way he interrupts the king when Misuzulu is speaking.