The ACT Party leader says former MP David Garrett has not confirmed to him that he intends resigning his seat in Parliament.
Radio New Zealand understands Mr Garrett will announce his intention to quit Parliament altogether on Thursday, when the House ends its current sitting session.
Mr Garrett was formally confirmed as independent MP earlier this week.
He resigned as an ACT list MP after admitting in Parliament last week that he used a dead child's identity to obtain a false passport in 1984.
ACT leader Rodney Hide says he has spoken to Mr Garrett on a daily basis, mainly to check on his well-being, including making a call on Wednesday.
However, he says Mr Garrett made no mention of whether or not he intends to resign as an MP, or when he might do it.
Mr Hide says Mr Garrett reiterated his intention to do the best thing for the party and the National-led Government, which the ACT Party supports.
Mr Hide says he believes he will still be secure in his leadership and he has no concerns about a potential shift of power.
The next person on the ACT list is Dunedin lawyer Hillary Calvert. Mr Hide says she has already expressed her support for him publicly, and he takes her at her word.