"It was one of the principal reasons for committing to the anti-ISIL fight that there are Australians there in significant numbers who wish to do us harm," he said. Any Australians fighting with ISIL had done so in full knowledge of the danger: Prime Minister Tony Abbott. Credit:Alex Ellinghausen "Now, if they are killed in conflict, they know the risks, they took their chances, they broke Australian law. "They are doing something which is a very serious offence under Australian law and I say again to any Australian who might be thinking of travelling to the Middle East to join in terrorist activity – don't." Security agencies say they are aware of some 60 Australians who have travelled to the region to fight with ISIL and related groups, and believe another 100 people in Australia also support the extremist campaign with funds, propaganda and recruiting.

Australian authorities are also concerned about an unknown number of people who may be considering travelling to Iraq to join the fight but who have yet to appear on the security "grid". The revelation came as Greens leader Christine Milne again attacked the government for following the US into another war, warning that it would make the security situation in Australia more perilous. "You have to be realistic about the fact that if Australia involves itself with the United States in a war in the Middle East, then there will be greater recruitment capacity from ISIL right around the world for disaffected young people," she said. Illustration: Cathy Wilcox

Mr Abbott stated again that the actions of the group calling itself Islamic State were fundamentally against Islam. "It is wrong, it is against God, it is against religion, it is against our common humanity," he said warning anyone considering joining the theatre of war that "it may well become much more dangerous because of the presence of Australian forces". He made the comments from Arnhem Land in the Northern Territory where he has positioned himself over the coming week. Australia's 600-strong contingent of air force personnel and specialist military advisers are in the process of being deployed to the United Arab Emirates where Australia has a base, Al Minhad. It is expected that the deployment will be almost completed within a week.

Sources close to the Prime Minister insist the government is acting because it believes it should and say it fully expects many Australians to oppose another military commitment. An SMS opinion poll released yesterday by Roy Morgan found a majority of voters currently back the action, but the issue remains finely balanced with 54 per cent approving of the forward deployment compared to 46 per cent against it. The poll was taken on Monday, less than 24 hours after the weekend announcement and surveyed 1239 electors across the country. Loading Mr Abbott has moved to scale back expectations of the Iraq foray, arguing military intervention is not an attempt to establish a pluralist democracy in the war-torn country but merely to defeat an enemy that would come looking for Australia if left unchecked.