Australian Prime Minister Julia Gillard says a multi-billion dollar offer for a coal mining company proves her proposed carbon emissions tax will not harm the vital industry.

Opposition lawmakers and coal industry leaders have denounced Ms. Gillard’s plan to impose a $24-a-ton tax on the nation’s top 500 polluters, arguing that it will force coal mining operations to shut down, costing thousands of jobs.

But Ms. Gillard says there is not “a better indication” that Australia’s coal mining industry is facing a good future than a $5 billion joint bid by U.S. mining firm Peabody Energy and European steel-making giant ArcelorMittal for Queensland state’s Macarthur Coal.

The Australian government is offering a $1.4 billion assistance package to the coal industry to ensure no jobs are lost.

The tax would take effect next July if approved by parliament.

The prime minister has seen her approval numbers plummet over her carbon emissions tax plan. A new voter opinion survey shows only 27 percent of Australians approve of the ruling Labor government, which is an all-time low.