It's set to be a big day for unions with the Fair Pay Agreements system coming into effect tomorrow.

It means eligible unions can apply to the Ministry of Business, Innovation and Employment for approval to begin bargaining for a specific industry.

The Council of Trade Unions President Richard Wagstaff says he understands many unions are ready to hit the ground running.

"Once they've initiated, then we'd expect the Ministry of Business, Innovation and Employment to verify their signatures and then there will be a process where employers will be notified."

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