MP's tirade on Transpower

National's Louise Upston now sits in judgment on New Zealand power giant. Photo / Supplied

State-owned company Transpower has been accused of "lying, perhaps criminally" - by a farmer who is now sitting in judgment as a Government MP.

Taupo MP Louise Upston is a member of a Parliamentary committee that reviews major Transpower projects, including how it manages fresh drinking water under its control.

But the Herald on Sunday has discovered that, while she was running for election, she and her husband Craig made a private submission opposing plans to run a new $824 million high-voltage transmission line near her home. In the submission, they accused Transpower of lying and "perhaps criminally" distorting information.

Upston made the submission to the environment minister in 2007, a year before she became an MP.

The state-owned electricity company wanted to run the 186km overhead line from Whakamaru, north of Taupo, as part of the North Island grid upgrade.

"Transpower has falsely (and perhaps criminally) tried to justify the need for this line being built by using out of date and inaccurately high demand growth forecasts ... and are providing misleading and inaccurate costings of the real alternative options," she wrote.

She also argued that electromagnetic field emissions from the line could be harmful to local children - a view that is based on disputed science.

But Upston was one of a large number of farmers who opposed the big pylons stalking across the dairy farms of the Waikato. Last year, farmer Steve Meier refused Transpower access to prune pine trees beneath existing pylons, which eventually arced, caught fire, and cut power to 50,000 homes.

Upston is now sitting on the Local Government and Environment Committee and major Transpower projects can fall into that category.

No such matters are currently before the committee, but last year, the committee said it would be closely following the Auditor-General's assessment of how Transpower manages its assets with regard to the supply of drinking water.

Upston told the Herald on Sunday she made the 2007 submission as a private resident, not as a politician.

She had since lobbied her fellow National MPs about her concerns, unsuccessfully.

"I lost," she said. "I voiced my concerns and nothing changed, which is kind of to be expected."

The Whakamaru transmission line project is now well underway, though a board of inquiry did place conditions on the process.

Upston said her select committee "didn't touch" any matters relating to the Whakamaru grid upgrade, her only area of concern. "I have no beef with Transpower," she insisted.

Asked if her personal opinion had changed, she said: "I'm not really in a position to have a personal opinion as an MP."

Transpower communications manager Rebecca Wilson would not comment on Upston's status as a member on the committee or her opposition to the project.