Australia's longest-serving Green Party senator Bob Brown says he is quitting politics in June to make way for new talent.
A former director of the Tasmanian Wilderness Society, Senator Brown, 67, started his political career as an MP in that state after leading a protest against construction of the Franklin hydro-electricity dam.
He built the Greens' national party from nothing until it became the third-biggest force in the Senate, but has told journalists that after 16 years in Canberra he was quitting as party leader and would also leave the Senate by June.
"I am 67. I am aware that one should always make room for renewal in politics," Senator Brown told the ABC in Canberra.
"A democracy is the healthier for the turnover of the depth of talent there is in its community".
Senator Brown leaves the Greens at historically high numbers in the parliament, with a total of 10 members in the House of Representatives and Senate.
The party has elected Senator Brown's deputy Christine Milne to the leadership, with Lower House MP Adam Bandt later voted in as deputy.
Prime Minister Julia Gillard thanked Senator Brown for a "remarkable contribution" to state and federal politics over the past three decades, including historic negotiations to help make the nation accountable for its greenhouse gas emissions.
He also campaigned for change supporting rights of same sex couples, highlighting the work with examples from his own experiences.