Their de facto leader is Bob Brown, a Tasmanian representative in the federal Senate.
An uncompromising, unashamedly left-wing environmental party, they have gained support at the expense of the Australian Democrats and to some extent the Australian Labor Party, to the point where they appear likely to supersede the Democrats as the "third force" in Australian politics and at some future stage control the balance of power in the federal senate. The effects on Australia's political dynamics remain to be seen, but may be substantial as the Greens appear far less likely to compromise with the major parties than the Democrats are.