Simon Bridges has called the bluff of his potential challengers, and has called National Party MPs to Parliament for a vote on the leadership midday Friday.
It is still not clear where the votes would fall if there is a direct challenge, with one well-placed MP - a Bridges supporter - telling RNZ it was a "line call".
The numbers were being done to see if there was enough support for an alternative ticket of Todd Muller and Nikki Kaye, but there had been no formal challenge.
Muller and Kaye are yet to make any comment about whether they will front and challenge Mr Bridges on Friday.
The phones have been running hot since a disastrous poll this week - putting the Opposition party at just 30 percent.
During his morning media round Mr Bridges said there would be a vote to settle the matter once and for all.
RNZ political editor Jane Patterson has the details.