NSW Greens MLC John Kaye is being remembered by colleagues as a politician of "enormous principle, energy and commitment" following his death from cancer at age 60.
It was revealed in February that Dr Kaye, who was elected to the upper house of the NSW parliament in 2007, had been diagnosed with cancer and would be unable to return to Parliament to resume his duties before the end of March.
The Greens announced the public education and renewable energy advocate passed away on Monday night after a battle with cancer.
"John passed away after a struggle with an aggressive cancer which developed in recent months. He died peacefully in his home surrounded by friends and family," fellow Greens MLC David Shoebridge said in a statement.
"John was a tireless champion of public education, leading the national debate on education funding with an unflagging commitment to TAFE and public schools.
"Our thoughts today are with John's partner Lynne, his sister and brothers Dina, Andrew and Stephen and their families".
NSW Premier Mike Baird said in a statement he was "deeply saddened to learn of the death of John Kaye".
"He was a formidable advocate of the causes in which he believed," Mr Baird said. "Despite our political differences I regarded him as a friend."
NSW Labor leader Luke Foley described Dr Kaye as one of the state's most formidable and effective politicians.
"He made an impact by dint of great intellect and sheer relentless energy," he said.
The former academic was first elected to NSW Parliament in 2007 after completing his PhD at the University of California, Berkeley and a stint as a lecturer in electrical engineering at the University of New South Wales. He was also an advocate for effective public services, consumer rights and securing a sustainable water supply.
Federation mourns the passing of John Kaye. A tireless champion of public education. More to follow. pic.twitter.com/2PZP0qmbgj— Teachers Federation (@TeachersFed) May 2, 2016
Dr Kaye was known as a tenacious campaigner for public education, particularly TAFE, and also campaigned hard against public funding of independent schools.
In April, despite enduring rounds of chemotherapy, Dr Kaye continued to rally online against private education funding, campaign against greyhound racing and slam funding cuts to TAFE.
His family had remained hopeful of a return to public life, thanking supporters in April for taking on additional duties in his absence. "He looks forward to working with all of you in the future on securing a more just, democratic, sustainable and peaceful NSW," they wrote in a statement.
Even while he was unable to to respond personally to messages of support as he was undergoing treatment, he asked his partner Lynne to ensure his thoughts on political debates got through to journalists. "John also asked me to express his total outrage at Federal plans to take over TAFE and privatise it completely," his partner would write in text messages.
When John fell sick, his partner wrote back to those who'd been messaging him. This last par made me smile. #nswpol pic.twitter.com/IbvPIF3XRS— Sophie Tarr (@sktarr) May 2, 2016
During his time in parliament Dr Kaye used his position in the parliament to rail against the influence of the alcohol and gambling lobbies on political parties, particular via political donations.
Dr Kaye and the Greens were the driving force, along with the former Labor government, behind the introduction of caps to donations to individual parties and candidates.
He also helped secure a ban on donations from the alcohol, tobacco and gambling industries, making the NSW campaign funding system the most robust in Australia.
Vale @johnkgreens pic.twitter.com/ZRQ5LrA9ob— Jeremy Buckingham (@greensjeremy) May 2, 2016
On Tuesday, former political foes also recognised Dr Kaye's contribution to the state.
"Sorry to learn of the death of [John Kaye]" wrote former NSW Premier Barry O'Farrell. "Despite many political battles I always enjoyed our chats on level 2".
Author and public education advocate Jane Caro said she was "devastated" to hear of Dr Kaye's death.
"A wonderful, funny, principled man who stood up [for] his beliefs, I liked him very much," she wrote on Twitter.
The Greens said a private service will be held this week at Waverley Cemetery, with further details available shortly.
So sad to hear about John Kaye. He was a passionate & tenacious politician & a lovely human being. Vale to one of the good guys #nswpol— Sarah Gerathy (@sarahgerathy) May 2, 2016
Incredibly saddened at early death of @johnkgreens. A superb man in every sense. Gave so much quality to political debate in NSW. Respect— Simon Chapman AO (@SimonChapman6) May 2, 2016
Sad to wake up to the news that Greens MP John Kaye has passed away. One of the very very good ones.— Caro Meldrum-Hanna (@caromeldrum) May 2, 2016