Family finances have taken centre stage in the General Election battle, with David Cameron pledging not to increase the three main taxes paid by households.
Mr Cameron is promising legislation to guarantee a "tax lock", banning rises in the rates of income tax, VAT or national insurance until May 2020.
Labour and the Lib Dems dismissed the pledge as a "gimmick".
David Cameron has not challenged Labour's claim that the Tories would cut tax credits in a speech in Birmingham this morning.
The Prime Minister said his party "should go on reforming welfare, to make sure that work always pays."
Asked about tax credits, Mr Cameron said that he wants to get people "off welfare and into work."
ITV News Europe Editor James Mates asked Mr Cameron: "Five years ago you promised not to raise VAT, is this promise designed now to convince a skeptical public that you won't break that promise again?"
Mr Cameron responded: "Unlike in 2009, 2010, I've seen the books, I've been doing this job for five years, I know what remains to be done."
Watch his response in full:
Millions of families' budgets are at risk if the Conservatives win the general election, Labour leader Ed Miliband has warned.
David Cameron is to pledge no increases in income tax, VAT or national insurance before May 2020 under a Conservative government.