First elected to the House of Representatives in 1987 Duncan spent his years in Parliament as an active parliamentarian serving on various legal and national-security related parliamentary committees.

Serving as Justice Minister in the Labor government from 1993 to 1996, Duncan supervised the development of the Keating Government’s Justice Statement. Kerr instigated major reforms in copyright, administrative law and legal aid. He initiated a Law Reform Commission report on improvements to Freedom of Information laws.

Duncan also secured passage of the Commonwealth Evidence Act 1995 and the Criminal Code Act 1995. He proposed and secured the passage of legislation to counter child sex tourism and comprehensively restructured Commonwealth law enforcement arrangements.

During Labor’s period in opposition from 1996, Duncan served in shadow ministry roles including Immigration, Environment, Arts, Justice and Customs.

Following the election of the Labor government on November 24, 2007, Duncan was appointed Parliamentary Secretary for Foreign Affairs (Pacific Island Affairs). In this role he took on the task of rebuilding stronger and more respectful relationships between Australia and the nations of our region.

In 2009 Duncan announced that he would not be recontesting his seat. By then he had built the margin in his seat of Denison, a Liberal-marginal seat when he first contested it, to over 16 per cent.