Families £500 worse off as tax changes bite, says think tank The number of hours that have to be worked before a family is entitled to working tax credits is also being increased. Currently a parent can qualify for the credit if they work 16 hours a week, that is being raised to 24 hours. Labour's shadow chancellor, Ed Balls, calculated that 212,000 working couples would be forced to increase their hours or face losing all their working tax credit. "Families on middle and low incomes are this weekend facing a tax credits bombshell from David Cameron and George Osborne," Mr Balls said. For all the Government's talk about increasing the personal allowance, these independent figures show that while they may be giving with one hand, they are taking much more away with the other. It cannot be the right priority to make millions of families and pensioners pay more so millionaires can pay less. Families will lose on average £500 despite the fact that Chancellor George Osborne has reduced the amount they will pay in income tax by raising the tax-free personal allowances by £630 to £8,105. The study by the IFS took into account this gain. The IFS figures also suggested that pensioners would be £315 a year worse off from April 2014 once the so-called "granny tax" - cuts to their tax-free allowances announced in the Budget - take effect. The Treasury rejected the IFS analysis and argued that most families and pensioners would be better off as a result of the Chancellor's decisions. A Treasury spokesman said: "From this Friday 24 million households will be £6.50 a week better off as a result of action taken by this Government.