The National Party saying no to a coalition with New Zealand First at this year's election is the result of a history of bad blood, according to a political commentator.
Leader Simon Bridges has ruled out any potential coalition agreement with Winston Peters.
Matthew Hooton says Bridges is relying on NZ First voters who don't like the Labour Party.
"There is a chance that this strategy will work," Hooton told Newshub.
Bridges said on Sunday he could not trust Peters and NZ First - Hooton said that demonstrates a lot of hurt.
"There's a strong personal element to this," Hooton said. "When you don't trust someone, what could be more personal than that?"
Hooton believes Bridges' decision was inevitable.
"What he's trying to do is establish this election as [the] Labour-Green-New Zealand First lot, and the National-ACT combination," said Hooton, adding more conservative voters may stick with NZ First should National slide in the polls.
Bridges is following the lead of former Prime Minister John Key, who ruled out working with Peters and NZ First in 2005 and 2008.
"I don't believe we can work with NZ First and have a constructive trusting relationship," Bridges said on Sunday.
"When National was negotiating in good faith with NZ First after the last election, its leader was suing key National MPs and staff. I don't trust NZ First and I don't believe New Zealanders can either."
Peters was unfazed by the announcement.
"Let me say this - he's [Bridges] got a lot to learn about politics. Narrowing your options can be the worst strategic move you will ever make," Peters said.