National says if you've done something bad enough to end up in prison, you shouldn't be allowed to vote.
Justice Minister Andrew Little announced on Saturday inmates serving sentences shorter than three years will have their voting rights restored ahead of the next election.
"This threshold of a three-year jail sentence means those prisoners will be able to vote on the Government that will be in power when they are released," said Little, following the advice of the Supreme Court and Waitangi Tribunal.
"This will ensure people sentenced to three years or more in prison can re-engage with the democratic process as easily as possible."
But National MP Mark Mitchell says the Government has got it all wrong:
"We've seen another announcement this week where they're not allowed to refer to them as prisoners anymore - it's completely consistent with the signals this Government has set from day one - and that is a big focus on reducing prison numbers."
It was reported this week prison guards are being encouraged - not necessarily mandated - to call prisoners "men in our care" in order to give them more dignity, a part of the rehabilitation process.
Corrections Minister Kelvin Davis has been open about wanting to reduce prisoner numbers. So far the prison population has dropped about 1000 since the Labour-NZ First Government came to power, with no reported rise in crime.
Each prisoner behind bars costs the taxpayer about $100,000 a year.
The voting rights change will affect around 2000 prisoners and return the law to what it was before 2010, when the-then National government removed voting rights from all sentenced prisoners - even those perhaps being held briefly, if their incarceration happened to coincide with an election.
"If you offend badly enough in our community that you receive a prison sentence - it's very hard to get a prison sentence in New Zealand - then you lose some rights," says Mitchell. "One of those rights is the right to vote."
It will come into place before the next election. Little had previously said it wasn't a priority.
National leader Simon Bridges, when he became leader of the party, didn't even know prisoners couldn't vote and appeared to back prisoners on short sentences being able to vote, before changing his mind after being corrected.
The Waitangi Tribunal said the ban was a breach of the Treaty of Waitangi because Maori are disproportionately imprisoned compared to other groups. The Supreme Court said it breached the Bill of Rights.
Green Party justice spokesperson Golriz Ghahraman welcomed the move as a good start to ensuring equal access to democracy.
"New Zealand should be a place where no matter your circumstances you have a right to cast a vote. Considering our proud history fighting for the women's right to vote, I think many would be shocked to hear that right now incarcerated New Zealanders, predominantly Māori, are deprived of this basic liberty."
The change won't directly improve Labour's chances of re-election - a few thousand votes from inside prison will have little effect on an election which will see close to 3 million people cast votes.
In 2010 the Attorney-General was National MP Chris Finlayson. He said last year he wasn't opposed to the ban being lifted.
"I'd just simply vote to make it Bill of Rights compliant, I don't think it's the end of the world if a few crims exercise the right to vote - they'd probably vote New Zealand First anyway."