But the leader of the party that has emerged a clear winner from Saturday's election has pledged not to use his influence recklessly.
"You will know that I'm not a demander. The Greens aren't into demands, but we are into getting the best outcome through negotiation," he said.
He begun discussions yesterday with Prime Minister Julia Gillard and Opposition Leader Tony Abbott about forming government.
No matter which party takes power, it is likely they will only be able to govern with the support of three re-elected rural independents, along with incoming Green Adam Bandt and possibly independent Andrew Wilkie if he clinches Denison in Tasmania.
"I don't know that Adam's met Tony, but I've told him I quite like him, as I like Julia Gillard ... we are a liking lot," Senator Brown said.
Mr Bandt's victory in the seat of Melbourne makes him the party's first lower house MP elected at a general election.
Senator Brown said Mr Bandt's success and the fact the Greens will hold the balance of power in the Senate cements the party's place as a genuine third force in Australian politics.
"It's a greening of this nation and nowhere has it happened more than here in Melbourne," he told reporters.
"It's a historic part of the change of politics in this nation."
Senator Brown was elected to the federal parliament in 1996, after 10 years in Tasmania's state parliament.
He was re-elected to the Senate for a third term in 2007.
