AbaThembu King Buyelekhaya Dalindyebo also said he will no longer recognise Mandla Mandela as the chief of Mvezo.
Dalindyebo travelled to the Union Buildings in Pretoria on Wednesday to deliver this message to the Zuma.
But Dalindyebo had no intention of actually meeting the president – a man he claims is unworthy of his title and unbefitting of leading the country.
In his address he claimed Zuma favoured the Zulu king and gave that kingdom autonomy, while refusing to grant the abaThembu people the same independence.
"Zuma must leave the government and go back to Nkandla," Dalindyebo told journalists outside the Union Buildings on Thursday.
The king said his relationship with Zuma began to deteriorate some time ago, after the president appeared to ignore his requests. He said Zuma only had time for "the Zulu king [Goodwill Zwelithini]".
AbaThembu kingdom's resources
He said in years past, Dalindyebo and Zuma held private talks where matters concerning the country and the development of rural Eastern Cape were discussed. But those days are now over, the abaThembu king said.
"We have written a lot of correspondence concerning constitutional matters and infrastructure development but none of these letters ever managed to draw your [Zuma's] attention," Dalindyebo wrote in his memorandum.
He said he had received no feedback from the president about these issues. Dalindyebo then took a swipe at "principal chiefs" – such as Nelson Mandela's grandson Mandla Mandela – who he said were illegitimate, and said the government had not dedicated enough resources to the abaThembu kingdom for development.
"Another matter is the introduction of principal chiefs that are deemed to be independent or having absolute autonomy; and the other issue is the non-standardisation of protocols and budget allocations for South African kingdoms," he continued.
He also said he raised the legitimacy of these "so-called chiefs" to both the Eastern Cape government and the president, and that it was in vain.
"However, the presidency has chosen to prioritise the dethroning of the king [Dalindyebo]. The abaThembu royal kingdom is also part of this Constitution of the Republic of South Africa that goes with the autonomy and independence granted to other kingdoms, like the Zulu kingdom.
"We ask the president, would the president have dealt with this so-called dethroning of the king if it was the Zulu king?"
'Nefarious, sponsored agendas'
In a letter dated April 1 2013, the presidency wrote to Dalindyebo. But the abaThembu head claimed the letter was "littered with flaws" and "nefarious, sponsored agendas".
"We understand that while you are the president, you are also born into the royal family of Nxamala and this qualifies you to understand how to handle traditional matters. The way you have handled our matters is disappointing as a man who is known to be a traditionalist," Dalindyebo said.
"Your constant refusal to pay a visit to the [abaThembu] royal palace to address this matter is very concerning because you keep sending your ministers with no decision-making powers. We invite the president to avail himself personally on July 25 to respond to this communiqué."