Debus was the member for Blue Mountains, west of Sydney, from 1981 to 1988. He was Minister for Employment from 1984 to 1986 and Minister for Finance from 1984 to 1988. Debus was also member for Blue Mountains from 1995 to 2007. He has held several ministerial positions in the New South Wales Government, including the Minister for Finance, Co-operative Societies and Assistant Minister for Education ; the Minister for Corrective Services, Minister for Emergency Services and Minister Assisting the Minister for the Arts ; the Minister for Energy, Minister for Tourism, Minister for Corrective Services and Minister Assisting the Minister for the Arts ; the Minister for Energy, Minister for Tourism, Minister for Corrective Services, Minister for Emergency Services and Minister Assisting the Minister for the Arts ; the Minister for the Environment, Minister for Emergency Services, Minister for Corrective Services and Minister Assisting the Premier on the Arts ; the Attorney General, Minister for the Environment, Minister for Emergency Services, and Minister Assisting the Premier on the Arts ; and the Attorney General and Minister for the Environment. Debus oversaw by far the largest ever reorganisation, expansion and re-equipment of emergency services across New South Wales. He was the longest serving environment minister in any Australian jurisdiction and oversaw the expansion of the national park system of New South Wales by over one-third. He undertook other environmental policy initiatives including the first program in Australia to successfully purchase water licences for the restoration of environmental flows in inland rivers; cleaner production and remediation laws which included pioneering emission trading schemes to reduce pollution; and the introduction of the first Extended Producer Responsibility laws in Australia. He initiated the project to create an unbroken chain of protected areas and other lands managed for conservation to stretch 2800 km along the Great Divide of Eastern Australia. On 30 October 2006, he announced that he would retire from state politics at the 2007 state election.
On 16 November 2006, Debus was accused by Liberal Party leaderPeter Debnam under Parliamentary Privilege of being under investigation by the Police Integrity Commission. In response the Government released a NSW Police Service report stating that a minister had been the subject of complaints which were dismissed in 2003 as spurious and groundless. The report did not name the minister concerned as it was deemed to be 'not in the public interest'. When Debnam failed to provide evidence to support his claims, he was censured by Parliament for misleading the House. It was subsequently reported that Debnam's source for the accusation was a convicted bank robber and child sex offender with a long history of making unsubstantiated allegations.
Federal politics
On 30 March 2007 Debus confirmed longstanding rumours that he would seek preselection for the Federal seat of Macquarie. The seat had been redistributed to cover most of his state seat; he'd represented nearly all of the reconfigured Macquarie's eastern portion at one time or another. It had previously been a safe seat for then sitting member Kerry Bartlett of Liberal, but the redistribution made it notionally Labor; Bartlett needed a 0.5 percent swing to retain the seat. On 24 November 2007 Debus won the election for Macquarie with a strong swing to Labor as his party won government. On 29 November Kevin Rudd announced he would be part of his new ministry. He was appointed Minister for Home Affairs in Kevin Rudd's First Rudd Ministry on 3 December 2007. This was a new ministry, and he was responsible for domestic law enforcement, including the Australian Federal Police and the Australian Security Intelligence Organisation. On 6 June 2009, Prime Minister Kevin Rudd announced a cabinet reshuffle without Mr Debus, who, after 28 years in state and federal politics had decided to retire. Debus did not contest the 2010 federal election. It was revealed in October 2008 that the Australian Crime Commission had compiled a secret file on Debus, sparking condemnation by former and serving police officials. The file included details of his personal habits, views on police corruption and former Labor prime ministers.
Honours
On 13 June 2011, Debus was appointed as a Member of the Order of Australia for service to the Parliaments of Australia and New South Wales, to the development of an emergency response framework, through contributions to legal and environmental reforms, and to the community.