"You can think about in 1996 — you've got the Christian Democrats with Graeme Lee and then you also have Christian Heritage. So the way forward is to — actually, you would have to form a form of a coalition collectively together."
He added that a coalition with New Conservatives and the Coalition Party was "something that maybe we should consider".
The Christian Coalition, led by former National MP Lee and Christian Heritage leader Graham Capill, missed out on election after polling 4.33 per cent in 1996.
The Conservative Party reached 4 per cent in 2014 and was renamed New Conservatives after the departure of founder and leader Colin Craig.
Ngaro stressed that he had not made any decisions about forming a party, and had not got as far as drafting a constitution. But he said he would have to make up his mind soon because he did not want to disrupt the National Party's direction.
He said he was loyal to National and would not take any other MPs with him if he left.
But also added that MPs were "free to choose" if they left.