The tragic circumstances also mean Dunedin will soon have another member of Parliament.
Mr Collins, 49, a father of two, collapsed and died suddenly after taking part in a charity event in Auckland, just days after having made a well-received maiden speech in Parliament.
Green party co-leader James Shaw said the party was absolutely devastated and Mr Collins’ death was a profound shock to everyone.
"Aotearoa and the Green Party have lost one of the kindest, most dedicated champions of fairness and equality.
"He was such an authentic, genuine, warm man who had respect for everyone. It’s a model of politics that I aspire to and I hope more people will live up to that standard."
In the South, Taieri MP Ingrid Leary said Mr Collins was a larger than life person.
"[He was] a great orator and a man of principle, with a huge heart for his Pacific peoples. He will be sorely missed in South Auckland where he had made a significant impact as an advocate for Pacific health and education outcomes."
Although Mr Collins eventually went to the Greens, he was "like a brother" to the Labour Pacific and Māori caucuses who were feeling his death deeply, she said.
"Only last night we were meeting for the first time as a cross-Party Pacific Friendship Group and Efeso was there warming up the room with his big smile and gregarious presence. Our hearts are with his wife and two children at this difficult time," she said on Wednesday.
Dunedin MP Rachel Brooking said Mr Collins was very loved.
It was "incredibly tragic" to find out someone so young with two young children had died.
Ms Brooking said Mr Collins was really into working for his community in South Auckland and the Pasifika community as well.
She too had been at the same meeting as Mr Collins the previous night.
MP's were still processing the death of Mr Collins and were supporting each other across parties, she said.
Mr Collins’ death signals the entry of the third new Green MP to Parliament since the final election result was revealed.
Dunedin man Francisco Hernandez is ranked next after Dr Xu-Nan on the Green list, and would be expected to replace Mr Shaw when he leaves Parliament.
Mr Hernandez did not want to comment yesterday.
The House met briefly yesterday for party leaders to pay tribute to Mr Collins, before it adjourned for the rest of the week.
