The Government has been forced to abandon its most controversial change to the Resource Management Act (RMA) following Winston Peters' win in the Northland by-election.
The number of National MPs will drop to 59, so the Government no longer has a majority to pass all of its proposed changes.
Protecting the environment is at the heart of the RMA - spelled out in sections six and seven.
The Government has been keen to give equal weight to economic development but opponents say that would tip the balance away from protecting the environment.
Prime Minister John Key said there was no doubt they would have to rip up what they had got and go back to the drawing board.
"There's just no question that you've got to rip up what we've got now, go back to the drawing board and have another go," Mr Key told Morning Report.
"We just don't have the numbers ... We can go away and look at it but there's just no question it'll have to be a rewrite of those sections six and seven of the RMA.
"We're going to have to go back to either what the current law is, or something else that others will agree to. But they won't agree to much change, if any."
United Future, Labour, Maori Party respond
United Future leader Peter Dunne said the Prime Minister's response was a little frustrating.
"Had that attitude been adopted 18 months ago, then we wouldn't be in this situation now," he said.
"I've always said that, while I am not in the favour of any changes to the principles of the RMA, that I think there are process changes that can be made and we should be talking about them but, to date, those talks haven't been held."
Labour's environment spokesperson Megan Woods said the Government's plans had always been unpopular.
"What the Prime Minister should have learned, from the last time they tried to gut the environmental protections from the RMA, was that there wasn't the broad political support for this," she said.
"We've said all along that we'll look at sensible changes to the RMA."
She said cornerstone legislation such as the RMA should never be changed without genuine consultation with all political parties in Parliament.
"The Government hasn't brought the legislation to the table. We are yet to see any detail and that is what has been lacking from this Government - it is no surprise that they are now panicking and talking about ripping up documents."
Maori Party co-leader Marama Fox was keen to find some middle ground.
"We don't want to hold up economic progress in this country. We don't want to be seen as the ones who are stopping that from happening but, in the same breath, we will not put our environment at risk for our future generations in doing so," she said.
"So, yes, we need economic benefit for the country and the development of some of these things but not at all costs."
Mr Peters said New Zealand First was seeking to work with the Government on legislation that would change the lives of those in the regions - and he said that was not the RMA.
"We've seen these economies hollowed out, whilst money is sucked out for consumption and Auckland," he said.
"They can boast about the Auckland growth rate but, when it is largely consumption and not production, you can see what is going wrong with the north, you can see what is going wrong with the country."
Mr Key said it was still possible some process changes could be made to the act with the support of Mr Dunne or the Maori Party or both.