The R206-million security upgrade to President Jacob Zuma's Nkandla home, in KwaZulu-Natal, is "grotesque", Cosatu said on Tuesday.
"Cosatu does not question the need for the state to take adequate measures to secure the president and other public office bearers. This is a norm everywhere in the world," Congress of SA Trade Unions spokesman Patrick Craven said in a statement.
"[However]... for the government to spend such a grotesque amount of public money on any one person is shocking and grossly insensitive to the workers, the poor and the homeless."
On Sunday, Public Works Minister Thulas Nxesi said the government spent R206 million on security upgrades and consultants for Nkandla. Included in this amount was R135 million for the "operational needs" of various government departments, R71 million for consultants, and security features such as bullet-proof windows, security fencing, evacuation mechanisms, and fire-fighting equipment, he told reporters in Pretoria.
Also included in the total was R26 million to make changes to the project (variation orders).
Craven said office bearers who approved the use of money for the project needed to be held accountable.
"The amounts that the minister now concedes were spent vindicate our decision to ask the Public Protector and the Auditor General to investigate them to check if each of them can be morally justified."
He said Cosatu was concerned about the fact that Nxesi's Nkandla team uncovered evidence of irregularities in the appointment of service providers.
"We call for the publication of all the names of all the service providers, including the names of their directors and shareholders," Craven said.
"In particular we want to be assured no government official, including political leadership, is conflicted and or has benefited from what appears to be massive inflation of prices."
He said rural development was still an important issue and needed to be implemented regardless of who would benefit.
"Nkandla should not be prioritised, but treated just like every other rural community," Craven said.