PM Jacinda Ardern has dismissed Iain Lees-Galloway from his immigration and workplace relations roles for an inappropriate relationship with a former staffer.
Lees-Galloway will not stand at the election after admitting to the prime minister that he had had an affair with a former staffer.
Ardern said it became clear his position as a minister was untenable as it opened up allegations of improperly using his office.
She said she had lost confidence in him.
Look back at how events unfolding with RNZ's blog:
"He has not modelled the behaviour I expect as a Minister that is in charge of setting a standard and culture in work places," Ardern said.
In a statement, Lees-Galloway said he "accepts the Prime Minister's decision and apologises absolutely".
"I have acted completely inappropriately in my position and cannot continue as a Minister.
"I have apologised to my family for letting them down. Please appreciate their privacy.
"I also apologise to anyone who has been hurt by my actions."
Carmel Sepuloni will become the Minister for ACC, Andrew Little will become the Minister for Workplace Relations and Safety and Kris Faafoi will become Minister for Immigration.
Earlier today, National Party leader Judith Collins claimed she had received an allegation about a Labour Party MP.
Collins would not say what the allegation was but earlier today told Morning Report she passed on an allegation to Jacinda Ardern yesterday then told media about it this morning when asked.