United Future leader Peter Dunne says he hasn't decided whether he'll support a bill that would allow the Government Communications Security Bureau (GCSB) to spy on New Zealanders.
The Government is currently trying to rush the bill through Parliament.
Two weeks ago Mr Dunne was forced to resign as a minister after being accused of leaking a report on the GCSB.
Mr Dunne - whose vote could be crucial if the Maori Party votes against the bill - told TV3 he had concerns about the spy agency.
"I suspect for a lot of New Zealanders, the question they will ask themselves in this whole debate is just how certain they can be of their freedom, how certain they can be that they aren't inadvertently caught up in something much wider.
"And I think the challenge is to give the greatest level of confidence you can to people that their circumstances are being protected and their rights and freedoms are not being abused."
Peter Dunne said he would decide how he would vote when the bill comes back from the select committee.