"Ministry for Primary Industries (MPI) will be able to turn up to farmers' properties without getting a warrant and seize anything they want, unannounced and without cause.
Guy said National asked O'Connor to send the Bill to select committee during the two-week recess to allow public input and ensure there were no unintended consequences for farmers, but the Minister refused.
"National proposed amendments during the debate that an officer needs reasonable cause to suspect non-compliance with NAIT before entering the property.
"We also proposed that these wide-ranging warrantless powers being curtailed, so a NAIT officer can't seize property without obtaining a warrant.
"Unfortunately, both of these safeguard amendments were voted down by the Government."
He said National did successfully move an amendment that required the Minister to report to Parliament next year on how these expanded powers were being used.
"National reluctantly supported the legislation to improve NAIT's performance but remain gravely concerned about the process and invasion of farmer's privacy."
National MP Amy Adams was reported yesterday as saying no law change of this scale should be forced through Parliament without scrutiny.
RNZ reported O'Connor as saying, "We are not adding power, we are aligning the powers under the NAIT Act - which are currently inadequate - to that of the Search and Surveillance Act".
MPI said in a statement the changes go no further than powers that already exist under other acts, which allow officers to lawfully obtain information where non-compliance is an issue.
O'Connor said: "A well-functioning NAIT is a key part of our efforts to protect our vital primary industries from pests and disease".
Read more on Mycoplasma bovis here
"Farmers and industry have been asking MPI to increase compliance so that people who are not complying can be held to account."
Beef + Lamb New Zealand said it welcomed the Government's move.
Dave Harrison, B+LNZ's General Manager Policy and Advocacy, said: "Mycoplasma bovis has demonstrated that it is critical to be able to trace movements of animals between farms in the event of a biosecurity incursion and effective compliance forms an important part of that process.
"The amendments ... represent a good first step towards improving the NAIT system and provide greater clarity about enforcement.
"Those farmers who work hard to comply with NAIT requirements have increasingly been asking for stronger penalties and compliance actions against those who put the industry at risk and this will give them confidence that some action is being taken."
DairyNZ has backed the amendments.
"It's become clear over the past year, as we deal with the fall out of Mycoplasma bovis, that some farmers haven't been taking the requirements to record animal movements through NAIT as seriously as they should have been," chief executive Tim Mackle said.
"We've always encouraged farmers to ensure they complete NAIT records, and the failure to do so has caused significant problems for the sector since M. bovis was first discovered in New Zealand last year. Legislated changes to the Act were clearly necessary.
"M. bovis has proven just how difficult a disease like this can be for a herd, for the farming community, and for the wider economy."
