Miners glad to see back of MRRT THE mining industry says the former Labor government's minerals resource rent tax (MRRT) was an unnecessary impost and it's glad to see the back of it. Federal Treasurer Joe Hockey has introduced legislation to repeal the controversial MRRT and associated spending measures in federal parliament. "The bill ends a sordid history of poor taxation policy," Mr Hockey told MPs on Wednesday. Scrapping the mining tax and associated expenditure measures is expected to save the budget $13.4 billion. Mr Hockey said only Labor could have introduced a tax that raised little money and left the budget worse off. Since it began, the tax has raised a net $400 million - despite Labor's initial forecasts of more than $3.7 billion in its first year. Minerals Council of Australia chief Mitch Hooke said the MRRT was an unnecessary impost on industry. "Its repeal is all the more important when the industry is facing pressing challenges to improve productivity and cost competitiveness to encourage continued investment and growth," he said. Fewer than 20 individual taxpaying groups had contributed to the net $400 million raised so far. But Labor plans to vote against the bill because of the flow-on effects for superannuation and small business. The legislation seeks to scrap other measures associated to the MRRT package, including small business initiatives such as the loss carry-back initiative - where a company can retroactively apply net operating losses to a preceding year's income to reduce tax liability. The government has also used the cover of the mining tax to scrap the schoolkids cash bonus paid to parents, saving $4.5 billion. Opposition families spokeswoman Jenny Macklin described it as a "savage cut" to low and middle income families and "cruel hit" to parents trying to find the money to pay for school shoes and excursions. "This will hit struggling families hard, and it means their kids risk missing out on all the things they need to do well at school," she said. The bonus was never explicitly linked by Labor documentation to the MRRT legislation. It was a cash revamp of an earlier tax rebate program. The low income superannuation contribution is covered by the repeal package, but the government will keep incremental increases in the superannuation guarantee to 12 per cent - although the rises will be delayed for two years. The super guarantee rate is currently 9.25 per cent. It won't rise to 9.5 per cent until July 1, 2016 and will then increase by half a per cent a year until it reaches 12 per cent on July 1, 2020.