During the 1990s, Greig worked for a range of
Australian Labor Party politicians, including Senator
Peter Cook,
Diana Warnock MLA and Opposition Leaders Ian Taylor MLA and
Dr Carmen Lawrence MLA, but became disillusioned with Labor and joined the Democrats. He cited Labor's ‘weak’ commitment to LGBTI reform and was attracted to the work in this area by Democrats
Senator Sid Spindler, at that time creating on a commonwealth Sexual Orientation and Gender Identity (SOGI) Bill. Between 1995 and 1999, he was a local-government councillor in the
City of Vincent, becoming the first openly gay person elected to public office in Western Australia. At the
October 1998 federal election, aged 33, Greig was elected to the Senate. He used his maiden speech to acknowledge his homosexuality, highlight existing areas of discrimination and called for a range of national reforms in this area. It is considered to be the first time a federal politician had spoken so openly and strongly in favour of LGBTI rights, In August 2002, Greig became interim leader of the
Australian Democrats for six weeks following the ousting of former leader
Natasha Stott Despoja by senators including the party's deputy,
Aden Ridgeway. Ridgeway was expected to become the interim leader, though Greig, a supporter of Despoja, made a late challenge appealing to the Democrats governing National Executive to appoint him instead. Greig has been considered to be the first openly gay leader of an Australian political party. Greig was replaced in the resulting leadership ballot by
Andrew Bartlett in October, 2002. In the Senate, Greig had Democrat portfolio responsibilities for Attorney Generals, Justice and Customs; Family and Community Services; Transport; Resources; Fisheries; Disability and Sexuality Issues. He campaigned against internet censorship, and also served on the Joint Parliamentary Committee for the Australian Crime Commission and prompted it to investigate the trafficking of women into the Australian sex industry. Greig is mostly remembered for his pursuit of LGBTI issues, raising questions with Ministers, moving same-sex amendments to government legislation and triggering speeches from all parties on how to remedy commonwealth inequality against same-sex couples. In 2003, the conservative Howard Government which had opposed his agenda, reluctantly agreed to one of his campaigns and ended discrimination against same-sex couples in private sector Superannuation death benefits. Along with Spindler's SOGI Bill, his advocacy across all areas of federal LGBTI discrimination has been credited with laying the foundations for the Rudd Government's ‘Same-Sex Relationships (Equal Treatment in Commonwealth Laws General Law Reform) Bill 2008. In 2004, just prior to the election being called, Greig was one of only nine senators to vote against the ban on same-sex marriage by the Howard Government. That legislation triggered a movement for marriage equality that would last another 13 years. The ban was overturned in 2017 and Greig's pioneering speech and advocacy from 2004 was acknowledged by sitting senators and referenced in the media. During his term in office, Greig introduced three Private Member's Bills — one to outlaw
genocide in Australia, another to eliminate discrimination against LGBTI people, and another to promote government use of
open source software. All were blocked by the
Liberal–
National government. Greig stood for re-election at the
2004 election, but lost his seat to
Rachel Siewert of the
Australian Greens. His term expired 30 June 2005. ==Post-political career==