A High Court hearing into the validity of the Australian government's plain packaging laws for cigarettes has concluded.
British American Tobacco, Imperial Tobacco, Philip Morris and Japan Tobacco International have been challenging the laws which are due to come into effect in December this year.
Lawyers for the four companies have spent three days arguing the laws are unconstitutional, the ABC reports.
They say that by taking away their right to display branding on packaging and imposing a standard box, the government is acquiring their intellectual property without compensation.
But the Commonwealth Solicitor-General has argued the government is only regulating what can appear on packaging and is not gaining trademarks.
The laws specify all cigarette packets are to be the same shape with the same drab colour and print.
The tobacco companies are arguing the changes would extinguish their trademark, leaving only the names in a generic font as their distinguishing mark.
The full bench of the High Court has reserved its decision on Thursday.