National's delaying tactics have stalled the final debate on the Electoral Finance Bill until next Thursday.
That will force the Government to take urgency on other legislation either at the end of next week or in the week before Christmas.
The Government will avoid taking urgency to pass the electoral bill, to avoid inevitable accusations of ramming through constitutionally important legislation under urgency.
Different stages of the bill have to be debated on different sitting days, which means two more days of debate - completing the committee stage on Tuesday, and the third reading on Thursday.
Wednesday is set aside for private members' bills, so no Government business can be discussed.
National has sought to debate the bill for as long as it can.
It has not put up what could be described as frivolous amendments, but it has proposed so many amendments that voting on them has extended the time taken to consider the legislation.
National has confined its frivolity to question time, invoking a little-used right to ask many questions of the chairmen and chairwomen of select committees.
Yesterday, it and Act asked 10 more questions after the 12 ordinary questions.
Justice Minister Annette King said National's deputy leader, Bill English, had broken his word not to filibuster on the bill.
The party's shadow leader of the House, Gerry Brownlee, said all its amendments were substantive.
"We are very disappointed that the Government has decided it doesn't want to have reasonable debate on this," he said.