A survey suggests recent strike action has non-union members rethinking their stance.
A Waitato University report says more than half of non-union members support an automatic union default for new employees.
Council for Trade Unions president Richard Wagstaff told Mike Hosking the figures may have been affected by action taken by teachers and nurses.
Wagstaff it has given workers confidence about what can be achieved by collective bargaining.
"It will most likely give them a lot of confidence about what they are going to do heading into bargaining."
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