The Labour party says another government department appears to have been gagged in submissions to the Environment Protection Agency over the Ruataniwha Dam project.
It says documents show the Ministry for Primary Industries shared worries in a Department of Conservation draft submission that the Tukituki River could be harmed by the Hawke's Bay water project.
The proposed site of the $260 million Ruataniwha dam. Photo: RNZ
The DoC draft referred to concerns from the Ministry for Primary Industries about nutrient management, and economic impacts.
In its final submission to the EPA, the ministry says changes to water allocation and minimum flow rules on their own could have negative economic impacts.
But it says if done in conjunction with the Ruataniwha Dam, it could be economically beneficial.
Labour leader David Cunliffe says briefing papers show the ministry changed its tune on the economic impacts of the dam in its final submission.
Mr Cunliffe says this constitutes a major reversal of opinion from the ministry and he wants to know what prompted it.
"What we know from the DoC document is that the MPI draft had serious concerns both about phosphate toxicity and the net economic benefits. The final was much watered down in terms of the phosphate problem and suddenly the economics had turned positive."
Labour's claim came as the Government fended off accusations in Parliament of political interference by Conservation Minister Nick Smith in the DoC submission to the EPA. The Greens have called for him to quit.
Dr Smith has repeatedly said he did not know that a draft submission even existed until it was revealed by Radio New Zealand News on 17 September.
The 50-page draft, which said the dam could poison the Tukituki River, was replaced by a few lines in DoC's eventual submission.
On Wednesday afternoon Mr Cunliffe asked acting Prime Minister Bill English whether he or his office had sought an assurance from Dr Smith that he did not know about the draft earlier.
Mr English told the House he took his minister at his word when he said he didn't.
MPI says minister had no involvement
In a statement released on Wednesday night, MPI says its minister, Nathan Guy, gave no instructions on the content of its submission.
The ministry says it did not consult the minister on its submission and did not require or seek sign-off from him.
It says Mr Guy received a copy of the submission after it was lodged.
Planner quit for 'personal reasons'
The DoC planner who resigned after the draft proposal was watered down says she quit for personal reasons.
Radio New Zealand has been told the planner resigned in protest at the substantial draft submission being reduced to two paragraphs, with no mention of concerns that the dam could turn the river toxic.
The planner issued a statement on Wednesday afternoon confirming she was employed as a senior planner at DoC and decided to resign in August for personal reasons.
She says she has always maintained the professional ethics that public service roles require and will continue to do so, and will make no further comment.
A DOC spokesperson would not go into the reasons for the resignation last month, saying the department respects the privacy of the individual.
PSA wants independent inquiry
Meanwhile, the Public Service Association is calling for someone outside DoC to head an inquiry into leaked emails and a review of decision-making over the Ruataniwha submission.
It says DoC managers should not be reviewing their own decisions.
National secretary Brenda Pilott says current whistleblowing legislation is inadequate, with the email leak highlighting gaps in the way public servants can express legitimate worries.
"We think there's a real problem in that there's no clear process other than the Protected Disclosures Act for public servants to raise concerns. It's something we've raised before with the select committee looking into the Protected Disclosures Act but as yet there's been no movement on this question."
The PSA, which represents more than 1300 workers at the department, says it will be ensuring any members asked to take part in the inquiry are treated fairly and have proper support available.
Ms Pilott believes the DoC inquiry is already underway.
