"This is a clear breach of Parliamentary Service guidelines.
"I call on the leader of the party to open his leader's budget accounts to the scrutiny of the Speaker first and then the public of New Zealand."
Rules for parliamentary funding are intended to ensure the money is not used for party political purposes and the Parliamentary Service rules of conduct state that parliamentary staff, must, in the course of their work "avoid electioneering, political party business (i.e. acting for the non-parliamentary branch of the party, such as political party administration, fundraising or campaign related activities), and other actions that are party political in nature".
Mr Horan said the public had "a right to know what their money is being used for and whether it is being used legally" and last night confirmed he had lodged a complaint with Speaker David Carter. Mr Carter's office did not respond to requests for comment.
Mr Horan had previously indicated he was going to make the claims in Parliament yesterday but Mr Peters was not there to hear them.
When asked if he had deliberately avoided being in Parliament while Mr Horan made his claims, Mr Peters said: "Have you ever seen me run away from a fight?"
Mr Peters later confirmed he was in Auckland for a previously scheduled eye operation.
Meanwhile, Mr Horan had a fight of his own to make his claims as his former NZ First colleagues, Richard Prosser, Barbara Stewart and Andrew Williams, raised a series of points of order to try to block him.
Outside the House Mr Horan refused to repeat the claims without the protection of parliamentary privilege.
Mr Prosser said the allegations were "pretty wild, pretty spurious, and pretty sad".
Speaking from Auckland, Mr Peters said Mr Horan's claims were lies. While he confirmed NZ First had used parliamentary funding to develop the software, he denied the software was used for party political purposes.
"It's used to enable our expansion into sector groups, all sorts of commercial and social interest groups where we're able to spell out what our policies are and interact with them."
"It is run by someone who knows precisely what the law is as to the appropriateness of use and what you can and cannot do."
However he also said the software had not been launched yet.
He also dismissed internal documents obtained by Mr Horan which show discussion of the use of Vanguard for fundraising purposes.
Horan's allegations
• NZ First used about $20,000 from its taxpayer-funded leader's budget to purchase the Vanguard "constituent management software".
• Mr Horan claims Vanguard is used to seek memberships and donations which is against Parliament's rules.
• NZ First staff who are paid by Parliamentary Service are running the software which is also against Parliament's rules.