The Government clearly stuffed up new legislation to change MPs' pay in its haste to get it passed, the Green Party says.
The bill was to have been debated under urgency this week but has been sent back to the drafters for further work.
The legislation was to align MPs' pay to public sector pay rises after the Remuneration Authority determination last month gave MPs' a 3.5 percent payrise.
Prime Minister John Key insisted the delay was for technical reasons.
"It's to do with the Parliamentary Counsel Office's capacity to draft the technical issues around non-cash items.
"Now we can do it, but we just need to be absolutely sure it's technically right [because] we don't want to have to go back and fix it up," Mr Key said.
The Green Party calculated that the legislation would have actually resulted in larger pay rises.
Its co-leader Metiria Turei said the legislation was obviously pulled because it was full of embarrassing errors.
"The Government has stuffed up the legislation, they didn't get their maths right.
"Their bill would have increased MPs' pay by another $1000 this year, so they have to go back to the drawing board because they made such a massive mistake," she said.
But Workplace Relations Minister Michael Woodhouse said Ms Turei had again shown that not only did she not understand basic maths, but she didn't even understand her own pay slip.
He said the Greens did their calculations using base salaries rather than total MP remuneration - which was what the Remuneration Authority used.
"The Greens have completely done their sums wrong, I mean Metiria was talking yesterday about school lunches - I think she needs to go back to school and get do some remedial maths because the figures contained in her press release were just simply wrong."
Mr Woodhouse rejected any notion that the legislation had been stuffed up.
"It's a wild inaccuracy - there's been no botch-up, there's a small technical amendment that's required and I've asked my officials to take a little bit more time to lock it down and that's all there is, and it certainly would not have resulted in a higher increase for MPs."
Labour MP Chris Hipkins said Labour was still committed to dealing with the issue of MPs' pay but said it was a shame the Government was making such tough work of it.
"John Key has had five years to come up with something that's going to work, he's been complaining about it for five years - clearly he rushed something out that's unworkable," Mr Hipkins said.
The Government was confident the legislation would be before the house next week.
Ideally it needed to be passed before 25 March as that was when MPs' payrises were due to take effect.