Australia's Senate has voted to repeal the carbon tax, a levy on the 300 biggest polluters passed by the Labour Party when they were in power in 2011. Prime Minister Tony Abbott, whose Liberal coalition beat Labour in an election last year, had made the repeal a central aim of his government. Politicians have been locked in a fierce row about the tax for years.Labour says it helps to combat climate change, but the Liberals claim it penalises legitimate businesses.