National is adamant offenders who end up in jail do not deserve the right to vote.
The government is overturning the previous National government's ban and will allow inmates serving sentences of less than three years to vote at next year's general election.
The move was announced yesterday by Justice Minister Andrew Little.
He said the government plans to make the change to the Electoral Amendment Bill before the 2020 general election.
The law change will affect 1900 prisoners and means the law will return to how it was before a National-led government removed voting rights from all prisoners in 2010.
A Waitangi Tribunal report found the law change disproportionally impacted Māori prisoners and a High Court declaration stated the current law is inconsistent with the right to vote in the Bill of Rights Act.
But National Party leader Simon Bridges said many prisoners are by no means model citizens.
"We're talking about people who have possessed multiple child sexual abuse images; who've indecently assaulted multiple children; who have been involved in serious male assaults female [cases].
"This is not for very minor offending."
He said the government's plan puts criminals before victims and amounts to giving criminals back the voice they have taken away from others.
He promised National will restore the ban if it wins the next election.
Mr Little said restoring the right to vote meant current prisoners would have a say on the government that will be in power when they are released.
It would also address concerns that prisoners are not re-enrolling to vote once they leave prison.