First-term Green MP Holly Walker has decided to withdraw from the party's list, effectively stepping down as a MP at the September election.
"Unfortunately, a recent unexpected change in my family life has made it very difficult for me to continue as a Green MP", Ms Walker said.
"Under these circumstances, I have chosen to put my family first and withdraw myself from the Green Party list."
Ms Walker, who will still contest the Hutt South seat in order to help the Greens' party vote, said she was announcing the decision with "real sadness".
She said she had been juggling being a mother with her work as an MP for the last six months.