Maori Party co-leader Tariana Turia says Labour has all but blown its chances of a coalition deal at the next election.
The Maori Party is furious after details of the personal life of one of its candidates, Derek Fox, was released.
The Maori Party held an urgent meeting today in Auckland to discuss the allegations Mr Fox was heavy handed, with female partners in the past.
"I have done some things in the past that I regret now," Derek Fox said in a statement. "I surrendered myself to the authorities, I sought help to address those issues and I believe I am a very different person now."
It is understood that soon after accepting the Maori Party nomination in March, Mr Fox was threatened that allegations about his past would be made public.
Tariana Turia believes members of the Labour Party may be behind the leak.
The Maori Party are standing by their man, but are not willing to divulge what he is alleged to have done.
The government strongly denies having any involvement in Derek Fox's past being made public, but 3 News can confirm they received an advanced copy of the newspaper story yesterday from a staffer in the office of Labour Cabinet Minister, Shane Jones.
Prime Minister Helen Clark says Mr Jones did it on his own accord and has since been disciplined.
3 News