The Labour Party says it will not support the Government's police surveillance bill without four specific changes - including the removal of retrospective effect on current cases.
A parliamentary select committee has on Thursday concluded its public hearings on the Video Camera Surveillance (Temporary Measures) Bill, which the Government intends to pass under urgency.
The bill is in response to a recent Supreme Court ruling that the use of hidden cameras in an operation that culminated in police raids in Urewera in 2007 was illegal. The legislation allows police to resume using covert filming.
Labour says after hearing evidence presented to the Justice and Electoral select committee it has identified four bottom-line amendments.
They include ensuring that the police's power to use covert video surveillance is no broader than it before the Supreme Court ruling.
Labour also wants to stop the bill applying to current cases and investigations, and halve to six months, the length of time the temporary legislation will apply.
The party wants it made clear that no-one can seek to overturn a conviction or seek compensation simply because of the use of covert video surveillance.
The select committee has begun deliberations on the legislation and has until Monday to report back to Parliament. The Government intends to pass the bill under urgency next week.