The strike comes as a result of the failure by the Department of Social Development to table meaningful responses to their reasonable demands, since August 2015.
Last month, Nehawu mounted a nation-wide protest action where it delivered a memorandum of demands but a solution to the dispute is yet to be reached.
The union demands, among other things, the occupation specific dispensation for Social Service Professionals and Occupations, the introduction of rural allowance, the absorption of unemployed social workers on a permanent basis and many others.
"As Nehawu, we can no longer tolerate the arrogance and intransigency by the department, thus we have resolved to withdraw our labour power in support of our demands," said the union in a statement.
"We have used all the avenues to maintain labour peace and a national shutdown comes as a last resort to compel the department to meet our demands."
Nehawu blamed the Minister of Social Development, Bathabile Dlamini, for not taking serious their demands. "It is evident that the Minister is hell-bent on holding the sector and the country at large in ransom, as a result of her failure to exercise her oversight role.
Recently, Nehawu had to fight for the survival of the South African Council for Social Service Professions (SACSSP) which was on the brink of collapse under her watch," Nehawu said.
"We have also noted with disgust the Minister's interference with operations at Sassa, trying to prevent Nehawu from fighting nepotism in that agency, instructing the previous CEO to withdraw from progressive collective agreements entered into with the union in the SASSA National Bargaining Forum (SNBF)."
Nehawu said it would be convening the South Africa Social Security Agency (Sassa) national meeting to deal with the challenges in Sassa, and exploring a secondary strike in Sassa in support of the impending strike of its members in the Department of Social Development.