Labour leader Andrew Little has received a rapturous response at the Green Party annual general meeting this afternoon.
Days after Labour and the Greens signed a formal agreement to work together, Mr Little became the first Labour leader to speak at a Green Party conference.
Around 200 Green Party members - and a handful of Labour MPs - gave him a standing ovation at the Lincoln Events Centre in Christchurch.
Mr Little, standing in front of Labour and Green posters, said he agreed to speak at the conference out of a "profound sense of responsibility".
"We must show that there is a real alternative," he said. "A credible alternative."
His speech was well-received. The audience nodded along and gave an extended round of applause when Mr Little committed to combatting climate change and eliminating homelessness.
The speech was spent mostly on reiterating Labour's core political messaging - that the National-led Government was increasingly "out of touch".
Mr Little made no references to a potential Labour-Green Government or any possible coalition arrangements.
He touched only briefly on the Labour-Greens Memorandum of Understanding.
Labour had made good progress since its 2014 election defeat, he said.
"But in an MMP environment, that alone isn't enough.
"In our country, under our system, governments must be built on lasting, mature relationships between different parties that share a common vision for the future.
"That's why we've been strengthening our relationship and co-operation with the Greens."
"This is the moment."
In his keynote address, Green Party co-leader James Shaw made an appeal to Labour to stick with his party after the election in any potential coalition deal.
The two parties' MoU expires on election day, and Labour reserves the right to form a coalition with New Zealand First and shut out the Greens - as it did in 2005.
Mr Shaw made the case for a Labour-Greens coalition next year.
"I believe that a Labour-Green Government after next year's General Election is entirely possible," he said.
Mr Shaw was full of praise for the Labour Party and its leader Andrew Little.
Addressing the Labour leader in the front row, Mr Shaw said: "In the time I've gotten to know you, you've demonstrated to me that you're a person of great integrity. You are someone who brings people together ... That's why I want to work with you."
Mr Little's appearance at the AGM was a "break in the clouds", Mr Shaw said.
The two parties had different histories and values, but both wanted to "transform things for the better" and "find jobs and homes and hope for those that need them".
The Green co-leader's speech contained no new policy and was light on detail, though the party is expected to launch a big environmental campaign tomorrow.
The Greens are treating the AGM as the start of their 2017 campaign, and Mr Shaw's address was effectively an election stump speech.
"This is the moment," he began. "When New Zealand elects the first Labour-Green government in 18 months, this is the moment we will remember.
"We will look to the agreement that we signed with Labour this week.
"We will look to when Andrew Little joined us at our AGM."
Mr Shaw's speech had a strong focus on environmental issues.
The Green Party will place greater emphasis on its environmental credentials in the 2017 campaign, partly to keep grassroots members happy but also to reach out to voters who feel that National's eight years of focusing on economic growth has begun to take its toll on the environment.
This would not be at the expense of social and economic policies.
Before the speech, the party confirmed plans for Labour and Green leaders and finance spokespeople to hold meetings with business leaders around the country to spell out their economic vision.