It will also impact on the party's election campaign if it can not reach the 500 member threshold in time for the next election. Unregistered parties can not seek the party vote and do not qualify for any of the free radio or television advertising in the broadcasting allocation.
The party is running large advertisements on its website, saying the party has ``been at the Centre of Government for over 10 years'' and urging people to ``join now''. The website said its membership fees were $5 a year.
Mr Dunne, who is in Parliament as MP for Ohariu-Belmont, would not comment on the issue but Mr Gunston told Radio New Zealand he was ``disappointed.''
United Future started losing some of its key members before the last election including former president Denise Krum, who stood for National in 2011. That prompted speculation that the party would not survive beyond 2012.
United Future was formed in 2000 after Mr Dunne's centrist United New Zealand party merged with the Christian Future New Zealand party. It reached a high of eight MPs in 2002, but was unable to maintain those numbers. It supported both the former Labour Government and National, which now often relies on Mr Dunne's vote for a majority.
News of the cancellation tops off a bad week for Mr Dunne, who has faced allegations from NZ First leader Winston Peters that he leaked a report on the Government Communications and Security Bureau _ a claim Mr Dunne has denied.