Global giant Imperial Tobacco has launched a legal challenge against Australia's plain packaging for cigarettes, officials said Wednesday, becoming the third company to contest the plan. "Imperial Tobacco has filed a challenge which has some similarities to the British American Tobacco (BAT) challenge," a spokeswoman for Australia's High Court told AFP. Imperial said its challenge, filed Tuesday, would claim that laws passed last month mandating plain packets for tobacco products from December 2012 breached Australia's constitution by infringing intellectual property rights. Centred on its Peter Stuyvesant brand, Imperial's case will seek a High Court ruling to protect all of its tobacco products, which it says are worth "billions of dollars". "The High Court of Australia will now determine claims which include the validity of these unprecedented laws," Imperial Tobacco Australia (ITA) manager Melvin Ruigrok said in a statement. "Unchallenged, the Australian government would otherwise be able to simply take the intellectual property of legal entities." BAT has filed a similar constitutional challenge but it was not clear whether they would be heard together, the High Court spokeswoman said. Philip Morris is also suing Canberra over the plan, which will see cigarettes in drab packets with large, graphic health warnings showing diseased body parts and sick babies, while brand imagery and promotional text will be banned. Ruigrok said Australians were fully aware of smoking's health risks and described the packets as "anything but plain", with official messages to cover at least 75 percent of packet fronts and 90 percent of the back. "ITA supports tobacco regulation that is reasonable, proportionate and evidence-based," he said, warning of billions of dollars in compensation and legal costs. "Unfortunately, the Australian government?s plain packaging legislation is none of these things." Canberra says that tobacco use costs the country more than Aus$30 billion (US$30.8 billion) a year in healthcare and lost productivity and has vowed not to be deterred by the tobacco companies' legal campaigns. Australia would be the first country to mandate plain packaging, although New Zealand, Canada and Britain have considered a similar approach and are watching developments.