It's Whanganui or nothing for stubborn Green Party

Green co-leader Metiria Turei. Photo / Mark Mitchell

Wanganui faces at least a year's wait to get its "h" after the Green Party blocked moves to change the law quickly to ensure the name changes could apply sooner.

Land Information Minister Maurice Williamson decided in December Wanganui could officially be spelled either with or without the "h".

The decision followed years of debate and requires a law change which will also allow other places to officially have two names.

However, Mr Williamson's hopes of making the law change quickly were blocked when the Greens objected to including it in a mop-up bill which governments often use to make minor changes to a range of laws in one go.

Such bills require the consent of all parties in Parliament as they are supposed to be non-controversial.

Mr Williamson said the Greens refused, despite the Maori Party asking them to let it go through.

"It would have been brilliant, [the "h"] would already be in place. But the Greens just dug in," Mr Williamson said. Instead he will have to introduce a separate bill making the change - potentially delaying it for at least a year.

Green co-leader Metiria Turei confirmed her party blocked the change being made through the speedier process of a tidy-up bill.

She said the issue was not non-controversial and the Green Party believed Wanganui should have one spelling only - with the "h".

Her party would consider supporting the law change when Mr Williamson introduced the stand-alone bill.

"We will look at it, but we're not going to allow him to avoid making decisions by abusing the legislative process."

Mr Williamson hoped to introduce the bill by the end of the year but said it might not be passed for another year because it was not a matter of urgency.