The government and four tobacco giants are to face off in the High Court over Labor¡®s world-first laws requiring all cigarettes to be sold in plain packs.
The three-day hearing starts on Tuesday morning before the seven justices of the full court.
British American Tobacco (BAT), Philip Morris, Imperial Tobacco Australia and Japan Tobacco International claim the government¡®s legislation, which passed parliament in November, is unconstitutional.
They argue the Commonwealth is acquiring their property - in the form of brand names and logos - without just compensation.
But the government, in its submission to the High Court, says that¡®s rubbish because it is not getting any benefit.
Rather than taking over the companies¡® brands it says the legislation simply restricts their use ¡®in a manner appropriate and adapted to reducing harm to members of the public¡®.
Big tobacco is throwing everything at the legal challenge because it is worried other countries could follow Australia¡®s lead if the government wins the day.
BAT spokesman Scott McIntyre says the stoush will operate as a ¡®test case¡® on the validity of plain packaging legislation.
As a legal company selling a legal product we have continually said we will defend our property on behalf of our shareholders as any company would,¡® Mr McIntyre said in a statement on Monday.
However, Attorney-General Nicola Roxon believes the government is on strong legal ground.
Earlier this month she said: ¡®Plain packaging of tobacco products is a legitimate measure designed to achieve a fundamental objective - the protection of public health.
The Commonwealth argues that even if big tobacco could prove the government was acquiring their property rights the manufacturers still wouldn¡®t win in court.
That¡®s because the purpose of the plain packaging legislation - namely to improve public health - is within the scope of the Commonwealth¡®s legislative power under the constitution¡®s commerce, trade and external affairs powers.
The Queensland, ACT and the Northern Territory attorneys-general are all intervening in the High Court case along with the Cancer Council of Australia.
Labor¡®s laws will force all cigarettes to be sold in drab olive-brown packs from December 2012.