Abbott to take Aust back 50 years: TWU UNION boss Tony Sheldon says a big majority for Tony Abbott at the federal election will unleash forces wanting to take Australia back half a century and flood the labour market with 457 visa holders. Mr Sheldon, national secretary of the Transport Workers Union, says the election will be challenging and Labor is the underdog. "We have to fight right to the bitter end," he told ABC radio. This is a battle about Labor values. A thumping majority for (Opposition Leader) Tony Abbott means it will unleash all those forces that want to take us back 50 years. We need to make sure that 457 visa holders aren't flooding the market. Unions have long campaigned against 457 visas as a form of slavery but that stance was undermined when it emerged Mr Sheldon's union had hired three foreign staff on 457 visas. Mr Sheldon says the TWU only did this after advertising to fill the positions for many months. He says the conservatives have been "dog-whistling" that the union's stance on 457 visas is racist, but the union movement believes there is a place for 457 visas. However, tens of thousands of Australians wanted to work in the mining industry and people like mining magnate Gina Rinehart wanted to bring in foreign workers on lower rates of pay and work conditions, he said. Mr Sheldon said Jetstar flight attendants on 457 visas worked for $267 a month doing domestic flight attendant work. That is not on. That should be opposed by any government," he said. There is certainly a rorting of people's rights in this country.