New Zealand First has put the brakes on Labour's plan to repeal the three strikes law - dealing a major blow to Justice Minister Andrew Little.
Mr Little had been expected to bring the matter before Cabinet on Monday morning, but instead called a media conference to say that would not happen.
"New Zealand First have said they are not prepared to support the repeal of Three Strikes at this point," he told media.
"They didn't want that to be seen as separate from a broader programme of criminal justice reform."
Asked whether NZ First had pulled its support or reneged on a deal, Mr Little said that was a question for that party.
"I stand by all the judgments that I've made," he said.
"You don't get a paper before Cabinet that hasn't already gone before a variety of hoops and we had done that.
"But people reflect and we got to the point where I'm not putting the paper up."
Mr Little said New Zealand First was still committed to broader criminal justice reform - just not in "a piecemeal approach". The three-strikes law has been widely criticised by lawyers and academics.
A fuller reform package will be presented at a criminal justice summit in August.
Asked whether the three strikes repeal could reappear as part of that package, Mr Little said "everything is on the table".
The three strikes law - passed in 2010 - set up a three-stage system of increasing consequences for repeat serious violent offenders.
On a third 'strike', the sentence must be the maximum possible unless the court considers it would be manifestly unjust.
National leader Simon Bridges said the "embarrassing back down" underlined the cracks in the coalition government.
"The coalition parties have been found to not even be talking to each other and Andrew Little's comments about Three Strikes have been shown to be ill-advised bluster."
Mr Bridges said the government was making up policy on the hoof and had a "reckless" approach to law and order.
"These are incredibly serious matters but this is amateur hour stuff from a government quickly proving its incompetence."
Christchurch victim rights advocate Norm Withers congratulated New Zealand First for spiking the repeal.
Mr Withers started a law-and-order petition roughly two decades ago after his elderly mother was viciously beaten.
He said he was pleased that three strikes would stay.
"Quite frankly I believe Winston and the team have applied commonsense. They have always had a pretty strong view on law and order going back and I thought 'well if these guys turn around and support Mr Little, I will be deeply disappointed."
However, Victoria Univeristy criminology lecturer Liam Martin was worried the government's backdown might spell disaster for its promised wider justice reforms.
Mr Martin said it was deeply disappointing.
"Three strikes is failed American prison policy. It's a law named with a baseball slogan that doesn't even really make sense in New Zealand. So, I just hope New Zealand First won't derail the whole reform agenda on criminal justice. [It] has me worried about that."
Earlier today, Simon Bridges told Morning Report the law could reveal a divide between Labour and NZ First leader Winston Peters.
"We'll see the power dynamics of that and who's really in charge," Mr Bridges said.
"Winston Peters may take a slightly different view."
A number of victims of violent crime took out a full page advertisement in today's Herald against the repeal.
The open letter, backed by the Sensible Sentencing Trust, said "victims say no."
"We, the undersigned, are all personally the victims of serious violent crime, or close relatives of someone killed, maimed or sexually abused.
"We are all deeply concerned about the proposals to repeal the three strikes law, make bail easier, and generally to let people out of prison who need to be there," the letter read.