United Future has applied to the Electoral Commission for re-registration as a political party, but it's run into a problem.
It was deregistered on May 31 at its own request because it couldn't prove it had 500 members.
Party president Robin Gunston says there's been a surge in renewals and new members and it now has more than 500, but the commission is treating it as a new party.
"They regard this as the registration of a brand new party, not one just deregistered 11 days ago that they had previous information about," he said.
"For a new party they will only accept a signed paper copy of a member's application... we offered a full electronic record of all membership details requested plus a log of traceable electronic payments from members but it seems this does not suffice."
Mr Gunston says he's going to try to resolve the issue today.
The deregistration led to opposition demands that party leader Peter Dunne lose his parliamentary funding and be treated as an independent.
Labour and NZ First say the party doesn't exist and therefore he can't be its leader.
Speaker David Carter gave it time to sort itself out.
Mr Gunston says despite the uproar over the leaked GCSB report and Mr Dunne's resignation as revenue minister, the party has "huge levels of support".
The Electoral Commission usually takes six to eight weeks to validate membership lists.