Labor surplus plan can't be trusted: oppn The federal government's plan to get the budget back in the black within four years cannot be trusted, the opposition says. Treasurer Wayne Swan has told Fairfax newspapers he will map out a return to surplus by 2016-17 in Tuesday's budget. That suggests he is poised to announce deep spending cuts in what is his sixth and possibly final budget. But opposition frontbencher Scott Morrison says Australians cannot trust the government's assurances, particularly given its failure to bring the budget back to surplus this year as Mr Swan originally promised. "This treasurer has hopelessly failed to make true statements about the budget on every occasion," Mr Morrison told Sky News on Saturday. People just don't believe him just like they don't believe this government any more. He says the government has consistently failed to forecast both revenue and expenditure. And he's tipping another big blowout in asylum seeker management costs as boats continue to arrive in Australia at record rates. There has already been a $5.2 billion blowout in the immigration budget since the 2010 election, he says. There is increasing speculation the government will again raid its $5.2 billion foreign aid budget to help cover the cost of asylum seeker management. The government reallocated $375 million in foreign aid money to pay for asylum seekers in December, drawing a furious response from the Australian Greens and charity groups. Mr Morrison says the government should be upfront about its plans for the aid budget. Finance Minister Penny Wong says the budget will lay out Labor's plans to support jobs and growth. She has called on Opposition Leader Tony Abbott to flesh out his policies in his budget reply speech on Thursday. "Delivering the same slogans and empty rhetoric day after day is not good enough," Senator Wong said. Australians deserve to know what cuts he'll make, what he'll spend and what policies he'll introduce. Workplace Relations Minister Bill Shorten seized on reports that Liberal MPs have told Mr Abbott that his industrial relations policies, revealed earlier last week, don't go far enough. "The Liberal back bench have confirmed Work Choices is alive and well in the Liberal party room," Mr Shorten said in a statement.