The Human Rights Commission has given cautious support to the Government's spying reforms.
However, the human rights watchdog says it is concerned about the broad definition of national security in the legislation, which will come before Parliament tomorrow.
Chief commissioner David Rutherford said today that the proposed changes to laws governing the Security Intelligence Service (SIS) and the Government Communication Security Bureau (GCSB) addressed concerns the commission had previously raised about the agencies.
These concerns included stronger authorisation for spying warrants, greater oversight of the agencies, and strengthened requirements regarding compliance with human rights law.
Rutherford said the proposed changes were "a significant improvement" but there were aspects of the bill which were still a concern.
"Chief among these is the definition of national security," he said.
Changing the definition of national security is also a bottom line for the Labour Party, which says its support will not go beyond the first hurdle unless the definition is narrowed.
National security is currently defined in the legislation as protecting against potential or real threats to New Zealanders, to economic security, or to international relations.
However, the Government is concerned that this might not capture new and emerging security threats.
It is considering an alternative approach, in which the legislation does not define national security but instead lists the types of threats and activities that should be covered.
The Attorney-General and Commissioner of Intelligence Warrants would have discretion about what qualified as a threat to national security.
Having no formal definition of national security would allow agencies to be "adaptive to an ever-changing security environment", a Government briefing paper says.
The reforms follow a broad-ranging review by Sir Michael Cullen and Dame Patsy Reddy.
Among the main proposals in the legislation are a single warranting framework for both the domestic and foreign intelligence agencies and a new mandate for the GCSB to spy on New Zealanders.