Opponents, who assert that proposed laws allowing for secret preventive detention of suspects are unconstitutional, said debating the bill on the day of the 1 November Melbourne Cup was an abuse of power by Prime Minister John Howard.
The Cup is Australia's most popular sporting event and widely known as "the race that stops a nation."
"I've seen John Howard's government do some pretty low things over the years, but hiding behind the Melbourne Cup to introduce these shoot-to-kill laws into parliament and pass them through, well that's the lowest of the low," said Kim Beazley, leader of the opposition Labour Party.
Howard's coalition won control of both houses of parliament in elections last year and is currently preparing to push several controversial bills through the legislature.
Government officials have said the opposition will be given just 10 minutes to debate the anti-terrorist bill after its introduction on Tuesday, rather than the traditional two weeks.
The new laws would give security agencies "shoot-to-kill" powers when dealing with terrorist suspects and allow them to secretly detain persons suspected of having knowledge of a planned attack for up to 14 days.
The authorities will also be able to impose tight controls on the movement of suspects without judicial review and prosecute people deemed to be inciting violence.
The new laws give security
agencies shoot-to-kill powers
The legislation also proposes life imprisonment for people who fund an organisation deemed militant and would impose seven-year jail terms on people who back insurgencies where Australian troops are deployed.
A wide array of civil liberties groups, academic experts and Muslim organisations have condemned the legislation, saying the laws would violate human rights conventions and possibly Australia's constitution.
The heads of government of Australia's eight states and territories, who are all from the Labour Party, initially backed the new laws last month.
But as more details emerged, they said this week that provisions on preventive detention and allowing restrictions to be imposed on the movement of suspects may be unconstitutional.
They also said Howard had promised judicial oversight of the powers but failed to include it in the legislation, while slipping in a provision giving police shoot-to-kill powers that had never previously been discussed.
Protests brushed off
Howard has called a meeting of state and federal legal officials for later this week to discuss the constitutional issue.
"John Howard now has control of both the House of Representatives and the Senate, and if he wants to use his power in an arrogant, bloody-minded way, we don't have the numbers to stop him"
Arch Bevis, opposition homeland security spokesman
But he brushed off the protests over the timing of the bill.
"Parliament is sitting on Melbourne Cup day so the idea that parliament having decided to sit on Melbourne Cup day you somehow or other calibrate the legislations you introduce on that day is ridiculous," he said from Papua New Guinea, where he was attending a Pacific regional summit.
The Melbourne Cup is traditionally Australia's most watched sporting occasion.
Offices across the country virtually close down as people gather in restaurants and pubs for an extended lunch and to watch TV coverage of the midday race at Melbourne's Flemington track.
Opposition homeland security spokesman Arch Bevis said picking Melbourne Cup day to push the anti-terrorism law through parliament was "an extraordinary abuse of power, the likes of which I don't think anyone would remember".
"John Howard now has control of both the House of Representatives and the Senate, and if he wants to use his power in an arrogant, bloody-minded way, we don't have the numbers to stop him."