The National Party wants pay to be cut when workers stage partial strikes or work-to-rules.
In its election policy on industrial relations announced on Friday, National says workers can sometimes do very little work for months under the guise of a partial strike and still be paid.
The party says with approval from the Department of Labour, company executives should be able to cut some of their income.
The proposal would particularly affect groups such as nurses and fire fighters, who stage only partial strikes in order to maintain emergency cover.
Trade unions say National's proposal would harm low-paid workers who cannot afford full strike action.
Council of Trade Unions president Helen Kelly says it could increase disruption as workers move faster to all-out strike action fearing loss of money anyway.
"For very low-paid workers, it's intended to remove a form of industrial action that is often the only one they can afford. For groups like nurses, who are very reluctant to take strike action and often show their objection by doing things like refusing extra shifts, they'll actually be forced to take strike action.
But Business New Zealand is pleased, saying partial strikes are extremely damaging to industry.
Paul Mackay, of Business Zealand is pleased, saying the greatest industrial damage in New Zealand is caused by partial strikes.
"If we all accept that this country has got an awful lot of work to do on the productivity front, the idea that there's no penalty for deliberately slowing the boat down so that it won't arrive on time or won't deliver the goods has got to have some frustration attached to it.
"So I think what we're seeing now is the Government being prepared to say, 'If you want to frustrate productivity, be prepared for it to cost you something.'"
The election will be held on 26 November.