Despite the prospect of partial freezes in power bills, Labour still says there needs to be a sole state power purchasing agency.
Mighty River Power has control over what can be 60% of some household power bills.
The company promised on Wednesday it won't increase this until 2015 and Contact Energy is matching the commitment.
Consumer New Zealand says the freeze is one of the first signs of competition.
Labour and the Green Party want a new state agency to be the single buyer of power for households. They say there is a lack of competition.
Labour finance spokesperson David Parker said the price of hydro power is still too high and has continued to rise.