New Zealand First leader Winston Peters has invited leader of the National Party to take part in a public debate with him on Wednesday.
Mr Peters says he has sent a letter to John Key asking him to come along to a public meeting in Aotea Square in central Auckland.
Mr Key has warned that New Zealand First would be an unstable influence on a Labour-led government, and in turn, Mr Peters has said Mr Key is scaremongering.
Mr Peters says if Mr Key came to the meeting, he could explain his views in person.
"Well, you know I'd love to see a debate so that everybody can see what is on offer, who's got the experience, who's got the policies and who's got the argument - because New Zealanders need to know exactly what these issues are."