Australian Prime Minister Julia Gillard Monday intensified her campaign for a carbon tax as 140 prominent citizens joined calls backing her divisive proposal. Australians are among the world\'s worst per capita carbon polluters but plans for the tax aimed at cutting gases blamed for global warming have seen the government\'s popularity plummet to record lows due to fears over higher household bills. Gillard, who heads a fragile Labor coalition with the help of a Greens MP and several independents, has reportedly ordered her cabinet to \"blitz\" the public and sell the plan ahead of a carbon price announcement within weeks. \"Overwhelmingly Australians accept that climate change is real, and people do want to act,\" she told reporters in Sydney. \"Now I understand that people are a bit uncertain, they want to know what is the best way forward to deal with climate change. \"Well, as prime minister I will keep explaining to the Australian nation the best way forward for all of us is to put a price on carbon pollution.\" The prime minister also defended Hollywood A-lister Cate Blanchett\'s decision to speak out on the issue as part of a union and greens group-funded television advert which urges Australians to \"Say Yes\" to a tax on carbon. \"Now Cate Blanchett has had her voice heard on climate change, that\'s appropriate,\" Gillard said. \"Just as it\'s appropriate for Australians right across this country, going about their daily lives today, to have their voices heard on climate change.\" The wealthy Blanchett came under fire from some media on Sunday, which claimed she was out of touch with ordinary Australians who may struggle to cope with the higher electricity bills that could result from a carbon tax. Other prominent Australians, including former Liberal prime minister Malcolm Fraser and fellow high-profile party member John Hewson, joined the debate Monday by signing a letter urging carbon reform. The letter, endorsed by 140 Australians including Nobel-prize winning scientist Peter Doherty and writer Tim Winton, argues climate change is already impacting the country. \"We say \'Yes\' to a price on pollution and renewable energy investment, \'Yes\' to jobs and \'Yes\' to protecting our ecosystems, health and environment before it\'s too late,\" it states. The government has proposed a carbon tax be levied on major industrial polluters by July 1, 2012 with plans for a full emissions trading scheme in three to five years.