National leader Simon Bridges says the political poll that showed his party had gained support was the most similar to National's own polling.
Two polls released in the weekend had two different results - in one National leapfrogged Labour to take the lead but according to the other, Labour could govern alone for the first time.
The National Party was back ahead of Labour in the 1 News Colmar Brunton poll - up four points to 44 - while Labour was down six percentage points to 42. But the Newshub Reid Research poll Labour could govern alone for the first time with 50.8 percentage points compared to National, which dipped out of the 40s to 37.4 points.
Both polls had Mr Bridges trailing Judith Collins in the preferred Prime Minister stakes.
Mr Bridges tells Morning Report that while the polls "simply can't both be right", the 1 News Colmar Brunton poll was the most similar to the party's own polling.
Discussing the Budget breach saga, Mr Bridges again called for the resignation of Treasury secretary Gabriel Makhlouf, calling his position untenable.
"It's pretty simple fundamentally, the Treasury was advised that was no compromise, they are told it was simply a data-management issue, which effectively means 'look at yourselves Treasury, not at anyone else'. Despite that he talked about hacking, he referred this to the police... and the other issue here is the government sat back on a lie, and that's not right either."