KEY POINTS:
The Whirinaki power plant has used 7.6 million litres of diesel in the first three months of the year, the National Party says.
Energy spokesman Gerry Brownlee said the power plant, near Napier, was intended as an emergency backup to be used seldomly in dry years.
But he said the figures - from use over 32 days in the three-month period - suggested otherwise.
"Its increased use is more evidence that Labour has failed to future-proof our energy sector."
In February, Mr Brownlee said Whirinaki was "running flat out" and could be burning up to a million litres of diesel a day.
- NZPA