Nick Clegg has told David Cameron that his general election pledges to protect universal welfare payments such as child benefit and winter fuel payments for the elderly are unworkable.

The Deputy Prime Minister and his fellow Liberal Democrat ministers appear to be winning their battle to curb welfare handouts to the better off in order to protect the most vulnerable in society. But the proposed restrictions on so-called "middle-class welfare" could anger many Conservative MPs, who fear a backlash from their party's supporters.