"The Public Protector, advocate Thuli Madonsela, has noted with deep concern the extraordinary and unwarranted attacks on her person and office by the ANC, the office of its Chief Whip in Parliament, one of its alliance partners, and the leader of its women's league following the unfortunate leak and publishing of her confidential letter to President Jacob Zuma," spokeswoman Kgalalelo Masibi said in a statement.
"Her reading of the public statements and comments attributed to these parties is that there is an attempt to interfere with the functioning of her office in violation of Section 181(4) of the Constitution."
She said Madonsela called on the parties to respect the Constitution and allow her to do her job without fear or favour.
Madonsela reportedly wrote to Zuma recently that he was second-guessing the recommendations she made following her investigation into the R246 million spent on security upgrades to his Nkandla, KwaZulu-Natal, homestead.
In her report, "Secure in Comfort", Madonsela recommended Zuma repay money spent on upgrades not related to security, such as the swimming pool, cattle kraal, amphitheatre, and visitors' centre.
In his 20-page reply to her report, Zuma indicated Police Minister Nathi Nhleko needed to determine if he should repay any of the money spent on security upgrades at the homestead.
In response to Madonsela's leaked letter the African National Congress's Chief Whip Stone Sizani said the public protector should respect Parliament's handling of the Nkandla saga.
He said the report was before Parliament and an ad hoc committee, and that the legality of Madonsela's letter was questionable.
ANC spokesman Zizi Kodwa said the letter could be interpreted as undermining the parliamentary process, and its authority to process the matter.
The ANC called on the public protector to stop playing to the gallery and allow other constitutional entities to fulfil their role without interference and undue pressure.
Masibi on Monday said the public protector reiterated that Zuma had not responded to her report or communicated any remedial action. This was despite the presidency claiming he had.
"Nowhere in the purported response of the president to the public protector's report does the document state that it represents his comment on the report.
"In fact, in paragraph 7, the document in question specifically states that it is 'not a critique' of the public protector's report and that it 'offers no comment' on the contents of the public protector's report and that this was not reflective of the fact that the president was accepting the contents," she said.
Madonsela's office said she had indicated that if Zuma had submitted a response to her report, she would leave the evaluation of its adequacy to Parliament.
Nowhere in her letter to the president had Madonsela told Parliament what to do , said Masibi.