The covert surveillance bill would give police unnecessarily strong powers, the Labour Party has told Attorney-General Chris Finlayson.
Mr Finlayson will bring the bill to Parliament on Tuesday to sidestep a Supreme Court ruling and ensure police have authority to conduct covert video surveillance on private property, but it has yet to secure enough votes to ensure it will be passed.
He needs at least 62 and so far has 59, with Labour and ACT refusing to back it unless it goes to a select committee so expert evidence can be given on its provisions.
But Labour's justice spokesman Charles Chauvel has now raised problems that involve the provisions of the bill itself.
"It appears to authorise more or less all covert video surveillance in the course of a warrantless search," Mr Chauvel says in a letter to the Attorney-General.
"You have not explained why the bill would take police powers so far beyond the scope of what you have contended is necessary."
Parliament has only six sitting days left before adjourning for the election and Mr Finlayson wants the bill through quickly.
He has been talking to opposition parties but three - the Greens, the Mana Party and the Maori Party - have rejected the bill outright.
Now he has only Labour and ACT left, and has to persuade at least one of them to back the bill.
ACT's five votes would give him a bare majority while support from Labour would deliver strong support in Parliament.
Mr Finlayson was on Friday briefing the Bar Association, which also has concerns about the bill's provisions.
Prime Minister John Key said on Monday police had suspended 50 covert surveillance operations and 40 pending court cases could be affected unless Parliament acted quickly.
NZN