Should child benefit be limited to two children? Fionola Meredith & former Tory MP Edwina Currie disagree

Should child benefit be limited to to children? Conservative MP Ian Duncan Smith says it's a brilliant idea. But deputy Prime Minister and Lib Dem leader Nick Clegg isn't so keen. This all comes as the chancellor announced proposals for an extra £12bn in welfare cuts in the next parliament. If we have to cut the bill - is this the best way to do it?