The Minister of Energy is dismissing Meridian Energy's claim the Government's electricity reform will put the South Island's power supply at risk.
Under the changes, Meridian will lose ownership of the Lake Tekapo generation scheme to Genesis Energy, splitting the management of hydro power generation in the area.
In a letter to Government ministers, Meridian says that could result in inefficiencies that could endanger supply.
Energy Minister Gerry Brownlee says Meridian is making outrageous statements. He says Genesis and Mighty River Power already have a water management arrangement for Lake Taupo, proving competitors can co-operate successfully.