The Prime Minister says the Government Communications Security Bureau will have to get an extra warrant to look at communications it collects on cyber security matters, on top of the warrant it gets to obtain the information.
The extra warrant would not apply to the GCSB spying on people or undertaking surveillance on them.
John Key. Photo: RNZ
A statement from John Key's office says the Prime Minister can impose any conditions he wants on a cyber security warrant and Mr Key intends to restrict the Government's spy agency from accessing the content of New Zealanders' communications, including emails.
If a serious cyber intrusion was detected, the GCSB would have to apply for an extra warrant to look at the content, if it is relevant to a significant threat.
The statement says Mr Key would also expect the GCSB to get the individual's consent, unless there were very good reasons not to do so.
Mr Key says he'll talk about that more in his third reading speech, as that is what judges use to interpret laws.
Green Party co-leader Russel Norman says Mr Key went on television saying the GCSB could not look at emails and is now promising that it won't without his explicit say-so.
"We write the law so that it enforces what we want to happen, not that it's dependant on the promises of someone in office," he says.
Labour Party leader David Shearer says Mr Key's approach is ad hoc and mickey mouse.
He says if Mr Key was so concerned about the issue it should have been part of the legislation.
Mr Shearer says Mr Key needs to follow up his assurances with an amendment to change the GCSB bill.
