Osborne may have smacked us in the face, but Harman, Darling and co stabbed us in the back.
Panto season came early this year. Watching George Gideon Osborne take the floor on Tuesday to announce the execution of the welfare state  was a bit like being in the audience at a raucous Christmas show, with booing and howling on cue from the Labour benches as the Chancellor tore successive chunks out of sickness benefit, housing benefit, lone-parent support and the dole, before setting out plans for a wildly regressive VAT hike, a freeze on public-sector pay and a hefty tax break for businesses.
The sheer brazenness of it all felt farcical, almost unreal. You half expected Osborne to burst into a musical number about how fun it is to be the baddie, announce the closure of all orphanages and vanish from the Commons in a puff of green smoke.
The response from Labour and the liberal press has been equally pantomimic. After all, when a new cabinet, 80 per cent of whose members are in private life millionaires, pulverises welfare and housing with a fistful of broken sums before declaring that "We're all in this together", what can you really say except "Oh no, we're not"?
By far the most astute summary came from the activist and comedian Mark Thomas, who tweeted: "That wasn't so much a Budget as class war committed with a calculator." The controlled ferocity of the emergency Budget was almost kinky, presuming you have a fetish for being kicked repeatedly in the soul by a man with a stack of papers and a glass of mineral water.
Labour and the liberal press have condemned the proposals -- but the fiery indignation of Harriet Harman  and Alistair Darling  rings hollow when one considers that the groundwork for many of the proposed welfare cuts had already been done before Labour lost the election.
Uncomfortable as it may be for the left to recall, some of the most regressive changes in this Budget -- forcing lone parents with school-age children into work; sanctions for the mentally ill and the long-term jobless; elimination tests for sickness benefits -- were Labour policies a few short months ago.
As the liberal press laments the proposed rationing of disability living allowance, it seems to have forgotten that Labour has already cleaned up on every other benefit offered to the infirm.
In 2009, the Labour Representation Committee accused the government  of ripping off Tory welfare-reform proposals wholesale. They were right: Labour’s green paper on benefit reform and the then shadow cabinet’s proposals to downsize and privatise the welfare state were functionally identical.
In January, John Cruddas and Jonathan Rutherford explained  in an essay for New Statesman how Labour had "lost its way" on welfare, abandoning the long-term jobless and undermining state support for the most vulnerable, with tragic consequences .
Earlier this year, the BBC exposed the brutality  of the new Employment and Support Allowance tests, which are designed to deny sick people benefit by any means necessary and which have required patients dying of cancer to prove their incapacity by walking until they fall over.
Despite the absurdity of imposing punitive "incentives to work" in a climate where there is simply no work to be had, outliers like John McDonnell  who have spoken out against welfare reform were condemned as cranks. And during the election campaign, not one Labour MP made the strong case for social justice and a protective welfare state that so many of us ached to hear.
Osborne’s emergency Budget is class war and nothing else, unashamedly shoring up the private sector while stripping vital support from those who already have nothing. The bitter truth, however, is that Osborne would not have been able to get away with this if New Labour had not already laid the ideological foundation for the destruction of welfare in Britain.
For those of us who have lived at the sharp edge  of Labour’s welfare reforms, for those of us who have lost homes, friends and partners to poverty and unemployment, for those of us who have organised, campaigned and fought  to push stories about the savagery of benefit sanctions  into the press, the centre left’s sudden attack of conscience is colossally insulting.
For the young, the sick and the poor, the energy of Labour’s outrage over welfare reform has come far too late. The Guardian’s Jackie Ashley commented  that these cuts represent “the absolute triumph” of the Tories’ “softening-up process” -- but that process occurred under Labour.
At some point over the past decade, it became acceptable to stereotype families and communities as "scroungers", to scapegoat lone parents and the long-term jobless, and to imply that the long-term sick are merely malingering. Somehow, it became admissible to speak of poverty and hopelessness as "incentives to work".
Somehow, it became conscionable for the left to refer to welfare provision as "a drain on the state" rather than a central, vital function of the state. For the millions of us who have relied on meagre welfare support to survive the first dip of this recession, it was New Labour that held us down as we waited for the inevitable punches from the right.
And in one way, news of the coalition's outright assault on the life chances and dignity of the poor hurts a little less, because we saw it coming. Being smacked in the face is less painful than being stabbed in the back.
In the weeks and months to come, Labour might just begin to remember that it is not the party of business, the party of corporate Britain, but the party of Nye Bevan, Clement Attlee and Barbara Castle, the party of working people and the poor, the party of the NHS, of university grants, of Chartists and Levellers and Diggers and dreamers, of trade unions and of the welfare state.
Over the coming years of pain, Labour will serve the ordinary people of Britain best if it remembers its core values. For some of us, however, it may already be too late.