Mining magnate Clive Palmer says the Rudd government's resources tax will hit jobs in the industries that service the resources sector.
Mr Palmer, one of the largest donors to the Liberal National Party, said he had been demonised by the unions - in a TV advertising campaign - and the Labor government over his opposition to the resources super profits tax.
But he said unions should be concerned about its impact on jobs.
"Unions are supposed to have the best interest of their workers at heart so it staggers me that they are supporting legislation that will lead to a massive number of their own members jobs being taken offshore," he said in a statement.
"The fact they're devoting time to condemning me rather than responding to flaws in the proposed legislation shows an inexcusable lack of foresight for the future of the industry and the Australian economy.
"Unemployment in the resources sector will lead to unemployment in the service industries that operate in mining towns like Mackay or Kalgoorlie.
"Many of these towns rely on the mining community to fuel their own income and now they face massive uncertainty."
Mr Palmer said he has been forced to shelve two major mining projects, in WA and South Australia, that would each have created more than 3000 jobs and billions of dollars in revenue because of the proposed tax.