"If you think of the history of New Zealand of faith-based or values-based organisations or parties that have been there, they've often formed coalitions if they're to make it," the National list MP told Newshub Nation on Saturday.
Ngaro, ranked 20th on National's list in 2017, is considering splitting to form a Christian-based party. There has been speculation it's a deliberate ploy by National to create a coalition partner, with ACT stuck with a single MP and its share of the party vote falling in recent elections.
Ngaro says that's not true, and there's "nothing wrong with National" that's prompted his potential departure.
"People have been talking to me for some time, talking about the concerns that they have with the current Government's arrangements. Out of that, those conversations have come to a point where people have said maybe it is an option to set up a party."
But he admits would add to growing congestion for the Christian conservative vote. Coalition NZ, a new party led by Destiny Church matriarch Hannah Tamaki, entered the fray this week; and despite losing their founder and financial backer Colin Craig, the Conservative Party is plugging along as the New Conservative Party.
Ngaro says history suggests they'll need to team up if they're to breach the 5 percent threshold required to enter Parliament without an electorate seat.
"In 1996 you had the Christian Democrats with Graeme Lee and you also had Christian Heritage. The way forward is to actually, you would have to form a form of a coalition collectively together."
That year saw New Zealand hold its first election under MMP. The Christian Coalition, led by former National MP Graeme Lee, teamed up with Christian Heritage, led by Graham Capill - who was later discovered to be a paedophile.
That coalition narrowly missed out, getting 4.33 percent. The best any Christian party has managed since then was the Conservative Party's 4 percent in 2014.
Ngaro hasn't ruled out joining Coalition NZ itself, but strongly hinted against it in an interview published by NZME on Friday. He told Newshub Nation he wished them well.
Ngaro says he's yet to decide if he'll lead the new party, should it happen. But he wants to make a decision soon.
"The ball is in my court... Watch this space. Rest assured, I'm not going to leave people hanging."