Spokesman says policy is a response to a string of incidents in recent years
A hardline law and order policy by NZ First would offer greater protection to homeowners, farmers and shop keepers who shoot to kill intruders during home invasions or burglaries.
Along with a 40-year mandatory non-parole sentence for premeditated murder, NZ First wants the Crimes Act amended to give certainty overthe use of "reasonable force" for self-defence.
Ahead of the party's annual convention this weekend, law and order spokesman Richard Prosser said the policy was a response to a string of incidents that had seen farmers and shopkeepers in court over their use of firearms or even hockey sticks against would-be robbers.
Mr Prosser said so-called "castle doctrine" laws in some US states, which saw Texan Joe Horn acquitted after his 2007 fatal shooting of two men who had burgled his neighbour's home, were "so over the top that it wouldn't be something that I think anyone in New Zealand would give consideration to".
Mr Prosser said his proposed law would not allow dairy owners, for example, to keep a shotgun under the counter.
Northland farmer Paul McIntyre was tried and eventually acquitted of charges stemming from his 2002 shooting of one of three men trying to steal his farm bike.
He said current laws already provided legal protection in cases like his own.
"It just depends on how good your defence in court is."
However, if the law moved too far in giving legal protection to use deadly force, "people are going to go out and start attacking their neighbours, aren't they?
"It's going to open up a whole new can of worms."
NZ First Leader Winston Peters said that although people such as Mr McIntyre hadn't been convicted for using firearms to protect themselves or their property, "what they got was a massive legal bill for trying to defend their rights and I think that is appalling".