Earlier this week Unison announced further price increases, of between 9-23%, which will affect electricity consumers in the Hawke's Bay, Taupo and Rotorua regions.

In what may prove to be the first big test of the commission's new power price rules, commission chairperson Paula Rebstock today said that Unison's self-assessment last year indicated it had breached the price threshold. Now it had announced further price increases.

Rebstock said the commission took breaches of the thresholds seriously, and was prepared to investigate when necessary. "The thresholds assessment is a trigger for the commission to use when determining whether a formal investigation is required."

The commission had already asked Unison to provide more detailed information relating to its self-assessment and on any future prices increases it might be proposing. The deadline was January 30.