Former Green Party co-leader James Shaw will leave politics at the start of next month.
Shaw stepped down as co-leader in January, but remained at Parliament to unsuccessfully shepherd his members' bill through the House.
The bill - which would have changed the Bill of Rights to include the right to a sustainable environment - did not pass its first reading on Wednesday.
At the time of his resignation, Shaw said it had been a privilege to serve at climate change minister and Green Party co-leader.
"I'm very proud of what the Green Party has achieved over the last eight years. I would like to thank Green Party members and supporters for their incredible hard work and support over that time.
"The Green Party will continue to lead the fight to stop the climate crisis, restore and protect our wildernesses and wildlife, eliminate poverty, and honour Te Tiriti."
Green MP Chlöe Swarbrick announced soon after that she would run to be the next co-leader, and in March it was confirmed.
Dunedin-based activist and conservationist Alex Foulkes had put his hand up for the role but conceded defeat.
Swarbrick received 169 votes from party delegates, Foulkes received no votes.
Shaw will deliver his valedictory statement on 1 May.