National is blaming the Government for a large number of strikes.
Ministry of Business, Innovation and Employment and Inland Revenue staff taking industrial action next month, along with nurses and teachers.
National leader Simon Bridges says it's creating uncertainty.
"Labour ramped up expectations prior to the election and now they're paying the price.
"It's very clear what the tragedy of all of this is going to be, it's going to slow down our economy."
Mr Bridges says it's going to make business harder.
"The unions feel emboldened; their mates are now in government. They feel that because they've paid the piper, which is Labour, they get to play the tune."
In May, Prime Minister Jacinda Ardern said she "absolutely hopes" there can be resolution with nurses wanting better pay and working conditions.