Opposition parties say independent MP Peter Dunne should be made to repay any money he has spent this year as leader of United Future.
On Tuesday, Parliament's Speaker ruled that United Future is no longer recognised as a party for parliamentary purposes, losing more than $180,000 in annual funding.
New Zealand First leader, Winston Peters said the Speaker's decision should be backdated to 1 January, when he says the party failed to exist.
Labour agrees. It estimates Peter Dunne could owe about $40,000.
But the Speaker, David Carter, is ruling that out.