The Central Union of Municipalities of Greece met in Athens Friday and agreed to shut down city halls starting Monday to urge the parliament not to pass the measures, which are connected to the stiff reforms Greece agreed to as part of its financial bailout.
The controversial provisions involve jurisdiction over municipal employees and new government controls over spending by local officials.
A proposal at Friday's meeting for a mass resignation of the mayors was rejected in favor of the three-day shutdown, Ekathimerini reported.
Greece's major government and private-sector labor unions planned to stage a 24-hour general strike Tuesday.
Union journalists Saturday agreed to join the walkout, Ekathimerini said.