She represented the Australian Democrats from 1990 to 2002, and was her party's leader from 1997 – 2001.
After being deposed by Natasha Stott Despoja, she quit the party to sit as an independent senator in 2002, adopting the party designation Australian Progressive Alliance from 2003 until her electoral defeat in 2005.
As party leader, she controversially facilitated passage of the Howard Government's Goods and Services Tax (GST).