Not allowing prisoners to vote is being labelled a dangerous precedent, with claims it could be extended to other groups considered unfavourable.
Prisoner Arthur Taylor is representing himself in the High Court at Auckland today, arguing Prime Minister John Key shouldn't have been elected in Helensville, as Auckland Prison inmates were denied their right to vote.
Taylor says a 2010 amendment to the law which stopped them voting is dangerous, as parliamentarians shouldn't decide who can and can't elect them.
He said there was no telling who the amendment could be extended to, alleging refugees, beneficiaries, or those who earn less than $28,000 could all be on the list.
Taylor also said a high proportion of the prison population were Maori, so the issue was not just about human rights, but also respecting the Treaty of Waitangi.
He said his supporters had checked Hansard records, and Treaty issues were never raised when the amendment was debated in Parliament.
Taylor has launched a bid from prison to overturn John Key's election result, saying those in Auckland Prison were denied their voting rights.
He was put in the dock this morning but objected to that, saying it would be difficult to present his case from there.
The hearing at the High Court at Auckland was adjourned briefly while staff tried to find another space for him.
A compromise was found by giving him a lecturn and mic, although he remained in the dock.
Inmates are banned from voting, and Taylor argues that banning prisoners from voting is inconsistent with the New Zealand Bill of Rights.
Up until 2010 prisoners serving sentences under three years could vote.