The National Distribution Union says workers around the country are expressing anger at Government moves they believe will weaken their work rights.
The union holds stopwork meetings every August, and says this year, the meetings have coincided with the Government's proposed changes to the Employment Relations and Holidays Acts, tabled in Parliament this week.
Some 400 West Auckland union members who met in Henderson on Tuesday condemned the planned changes, which include an extension of the 90-day work trial and limitations to union access to the workplace.
The National Distribution Union says delegates hope to meet the Prime Minister John Key to discuss their fears.
The union's general secretary, Robert Reid, says rallies this weekend in Auckland, Wellington, Christchurch and Dunedin will mark the beginning of a concerted campaign against the proposed employment law changes.
Stopwork meetings were scheduled in Dunedin, New Plymouth and Northland on Wednesday.