A parliamentary select committee inquiry into milk prices is "premature and confusing" given an inter-departmental review of regulations is still to be completed, Federated Farmers dairy section chairman Willy Leferink believes.
The select committee inquiry will be launched after National's caucus confirmed yesterday it would support it.
Prime Minister John Key said the inquiry still needed the support of the other political parties on the commerce select committee.
However, that support was unlikely to be a stumbling block with both Labour and the Greens pushing for an inquiry since the Commerce Commission decided last week not to hold a formal investigation.
Asked whether the inquiry could result in law changes to control prices, Mr Key said he did not want to pre-judge the outcome.
In June, three Government ministries - Agriculture and Forestry, Economic Development and Treasury - announced they had launched a separate inquiry into prices.
Mr Leferink believed it was premature to hold a select committee inquiry when the interdepartmental review was still to report.
"Even the Commerce Commission noted this in its recent analysis while MAF has reported separately on the milk price issue as well," he said in a statement.
Raw milk regulations under the Dairy Industry Restructuring Act and the farm gate price paid to farmers were interlinkedIt would have been far wiser for those findings to come before considering a select committee inquiry "as we're in cart before horse territory", he said.
Federated Farmers would represent dairy farmers at any milk pricing inquiry. Farmers had nothing to hide as there was a "fair amount" of analysis already in the public domain, Mr Leferink said.
On TVNZ's Q + A programme, it was pointed out that retail milk prices had increased 23% over the past five years but, over the same period, inflation increased by 16%.
"It seems we're going into another milk price inquiry because over five years, milk prices increased 7% higher than inflation.
"On that basis, we should hold select committee inquiries into council rates, government spending, the emissions trading scheme and even replica sporting gear," he said.
Mr Key was concerned a select committee inquiry could "cut across" the work of the inter-departmental group and indicated it should be "highly directed at where it makes sense".
The select committee itself would determine the terms of reference and call for submissions.
Committee chairwoman Lianne Dalziel was hopeful hearings could be held and a report presented to Parliament ahead of the election. There were many issues to look at and not much time, she said.