Deputy Prime Minister Nick Clegg has been confronted by a former Liberal Democrat councillor who told him he had torn up his party membership card because he was ashamed of what they were doing in Government.
The clash came as the Liberal Democrat leader held the first of a weekly Call Clegg phone-in on London's LBC 97.3 radio.
Mr Clegg has said he is doing the programme, with presenter Nick Ferrari, because he feels politicians do not hear enough from voters directly, and one caller told him his decision to take part was "very commendable".
But caller John, from Woking, told him: "I'm a Liberal Democrat who's just torn up his membership card. I joined in 1973 and I'm afraid I can't now say I want to represent the Liberal Democrats. I'm an ex-county councillor in Surrey and I am ashamed of what the party's doing."
He challenged Mr Clegg to explain how he could reconcile the party's principles with "this Government's attacks on the poorest in society".
Mr Clegg asked John to give the party credit for measures like raising the income tax threshold and introducing a pupil premium for children from disadvantaged backgrounds.
He insisted: "I am immensely proud that, facing the biggest crisis this country has seen in a generation, the Liberal Democrats took a big, collective and brave decision - at some political cost - to say we are going to step up to the plate ... and fix this mess while also trying to make society fairer."
The Deputy Prime Minister repeated his apology for committing the Lib Dems not to raise tuition fees when they were not in a position to deliver on the promise. In a wide-ranging half-hour of questions, Mr Clegg was also challenged over benefit cuts, international aid and job losses in the military.
The most bizarre question was saved until last, when Harry, from Sheffield, asked him if he had ever worn a onesie. A laughing DPM answered: "I was actually given a big green onesie in Sheffield, which I have kept in its packaging, but I haven't worn it yet."
Asked by Ferrari whether he would be willing to don the item in public for charity, he replied: "It's almost certainly something I would do in the privacy of my own home."