David Cameron has defended tax and benefit

David Cameron has defended tax and benefit changes which begin on Friday, saying 24m taxpayers will benefit from changes in personal allowances.

The amount of income that is tax free is rising by £630 to £8,105. The value of some benefits will rise by 5.2%.

But the time couples with children will have to work to qualify for working tax credits will rise from 16 to 24 hours.

Labour quoted research showing such couples would on average be £511 a year worse off.

The 6 April beginning of the tax year sees a significant number of changes to tax and benefits - affecting personal and family finances.

Measures which were announced by the government in the 2011 Budget, as well as last year's autumn statement, are now taking effect.

They range from increasing the first chunk of income that is tax free - known as the personal allowance - to the annual upgrading of benefits, as well as specific spending cuts.

Among the most important changes are:

• Benefits such as jobseeker's allowance, income support, disability benefits, maternity benefits and incapacity benefit are rising by 5.2% - in line with the CPI measure of inflation last September (announced in November 2011)
• Other than a few exceptions, couples with children will have to work for 24 hours a week between them, not 16, in order to qualify for working tax credit. One member of the couple will have to work for at least 16 hours a week (announced in November 2011)
• The child element of child tax credits is to rise by £135 but the couple and lone-parent elements of working tax credit are being frozen (announced in November 2011)
• The tax-free personal allowance for those under 65 will rise by £630 to £8,105 (announced in March 2011)
• For 65- to 74-year-olds with an income of up to £24,000, the personal allowance rises from £9,940 to £10,500 (announced in March 2011)