By: Seumas Milne - Twitter: @SeumasMilne

It's not just the scale of the walkout but the breadth that sets it apart: the 'big society', but not as Cameron meant it

Protesters on Victoria Embankment in London during the public sector rally. Up to two million took part in the day of action. Photograph: Dan Kitwood/Getty

It was the wrong time to call a strike. Industrial action would inflict "huge damage" on the economy. It would make no difference. Public sector workers wouldn't turn out and public opinion would be against them. Downing Street was said to be "privately delighted" the unions had "fallen into their trap".

The campaign against today's day of action has been ramped up for weeks, and in recent days has verged on the hysterical. The Mail claimed the street cleaners and care workers striking to defend their pensions were holding the country to "ransom", led by "monsters", while Rupert Murdoch's Sun called them "reckless" and "selfish".

Michael Gove and David Cameron reached for the spirit of the 1980s, the education secretary damning strike leaders as "hardliners itching for a fight", and the prime minister condemning the walkouts as the "height of irresponsibility", while also insisting on the day they had been a "damp squib".

But up to two million public employees, from teachers and nurses to dinner ladies, ignored them and staged Britain's biggest strike for more than 30 years. The absurd government rhetoric about gold-plated public pensions – 50% get £5,600 or less – clearly backfired.

It's not just the scale of the strike, though, but its breadth, from headteachers to school cleaners in every part of the country, that has set it apart. Most of those taking action were women, and the majority had never been on strike before. This has been the "big society" in action, but not as Cameron meant it.

And despite the best efforts of ministers and media, it has attracted strong public sympathy. The balance of opinion has varied depending on the question, but a BBC ComRes poll last week found 61% agreeing that public service workers were "justified in going on strike over changes to their pensions".

Of course that might well change if the dispute and service disruption drags on. But the day's mass walkouts should help bury the toxic political legacy of the winter of discontent – that large-scale public sector strikes can never win public support and are terminal for any politician that doesn't denounce and face them down.

The Tory leadership is unmistakably locked into that Thatcher-era mindset. Not only did George Osborne's autumn statement this week respond to the failure of his austerity programme by piling on more of the same for years to come, it was also the most nakedly class budget since Nigel Lawson hacked a third off the tax rate for the rich in 1988.

Any claim that "we're all in this together" can now only be an object of ridicule after Osborne coolly slashed child tax credit for the low paid, propelling 100,000 more children into poverty, to fund new bypasses and lower fuel duty.

And by announcing a 16% cut in public sector pay and benefits by 2015 along with a loss of 710,000 jobs, the chancellor declared war on his own workforce. Add to that the threat of less employment protection to sweeten privatisation deals and an end to national pay scales, and Osborne couldn't have made a stronger case for industrial action.

Public service workers are right to strike because that's the only way they can defend their pensions from Osborne's 3.2% raid and the only reason the government has made any concessions at all. They are also protecting public services from a race to the bottom in pay and conditions which can only erode their quality.

And far from damaging the economy, which is being dragged down by lack of demand and investment, the more successful they are in resisting cuts and protecting their living standards the more they will contribute to keeping it afloat.

But today's strike and whatever action follows it isn't just about pensions. It's also about resisting a drive to make public service workers pay for a crisis they have no responsibility for – while the bloated incomes of those in the financial and corporate sector who actually caused the havoc scandalously continue to swell.

When real incomes are being forced down for the majority, as directors' pay has risen 49% and bank bonuses have topped £14bn, that's an aim most people have no problem identifying with. Across the entire workforce there's little disagreement about who's been "reckless" and "greedy" – and it isn't public service workers.

As one Leeds gardener on £15,000 a year told the Guardian, striking was the only way to get the desperation of the low-paid on to the agenda of the wealthy: "they just don't have any idea of what it's like to live on pay like ours".

Cameron and Osborne's strategy from the start has been to divide the public sector workforce from the rest, hammer them to win extra market credibility – and convince private sector workers they'd be better off if education and health service pensions could be driven down to the often miserable or nonexistent level of most of the private sector.

The Conservative policy minister, Oliver Letwin, gave a taste of what else they have in mind when he told a consultancy firm that public services could only be reformed with "some real discipline and some fear".

But it looks as though ministers may have miscalculated. The message of striking public service workers chimes with the public mood. Private sector Unilever workers have just voted to take industrial action to defend their own pensions.

A crucial factor in the dire state of private sector pensions – and the wider wealth grab and mushrooming of inequality over the past generation – has been the decline in trade union strength. The fall in union membership since the 1970s is an almost exact mirror image of the runaway increase in the share of national income taken by the top 1% over the same period.

That is the common experience across the world wherever neoliberal capitalism has held sway, as are the attacks on living standards and public services, strikes, occupations and riots that Britain has had a taste of in the last 18 months. Which is why today's walkouts have attracted support from Nicaragua to Bangladesh.

One strike isn't, of course, going to force the government to turn tail. After Osborne's pay and jobs battering, the likelihood must be of more industrial action, with no guarantee of success. But today was a powerful demonstration of democratic workplace strength – which offers a chance to begin to turn the tide of a generation.