Middle-class militancy is in the air. Strike action turned the BBC news coverage back to the 1970s for one day at the end of May; public-service unions are threatening revolt; and even civil servants are restless and threatening to withdraw their labour.
Today's strikers wear collars in white, huddling not around the brazier but in the brasserie. For managers and leaders, especially in the public sector, the possibility of greater disruption is real, and rising. For users of these services, however, this could ironically be good news. While of course strikes bring short-term disruption, the evolving use of what is still quaintly called 'industrial' action means that public-service workers are sometimes battling to save the very notion of a public service.
The closing or diminution of public services inevitably makes headlines - as does a downing of tools by the news industry. But the rise is real: last year the number of working days lost as a result of strikes jumped to 905,000 - still a long way from the 7 million annual figure through the 1980s but double the amount of disruption in recent years. Critically, half the days of strike action were in the public sector.
The apparent revival of an appetite for industrial action has huge significance for the future of trade unions, the trajectory of public service reform and the prospects of improved working lives.
Trade union membership is already largely concentrated in the state-funded jobs: three in five public-service employees are in a union, compared to one in five in the private sector. And this gap is likely to accelerate as union members in mainstream businesses become even more of an oddity.
David Metcalf, an academic at the London School of Economics, warns in British Unions: Resurgence or Perdition (published by the Work Foundation) that 'private-sector unions are in the twilight zone'. He expects rates of union affiliation to drop to 12%, meaning that for this section of the labour market 'perdition is more likely than resurgence'.
The public sector is thus trade unionism's last redoubt. And the new generation of leaders in the sector - the so-called awkward squad - are more willing to consider the use of strike action among those workers providing public services.
Their bolder stance is made possible, too, by the lower risk of public opprobrium being heaped upon strikers than in the past. Whereas unions were once seen as acting only in the vested interests of their members and having undue influence over the Labour party, the reforms of the Thatcher years - in particular mandatory strike ballots seven days before any action and the banning of closed shops - have weakened their institutional power but vastly improved their PR. Public-sector unions have become skilled at explaining disputes as being in defence not simply of their members' jobs, conditions or wages but of the services on which we depend, too: health, fire brigade, benefits, education. The awkward squad are also the smart squad.
Unions are rediscovering, perhaps just in time, the importance of what economist Alan Flanders described 40 years ago as 'sword of justice' purpose, as opposed to their 'vested interest' function. As justice-makers, unions are concerned with equal pay and family-friendly policies, but also with the fabric of public life. They are agents of positive change rather than protectors of a privileged cadre. What Flanders dubbed the 'stirring music' side of union activity is supported by the positive associations between levels of unionisation and equal pay, flexible working and other workplace benefits. Metcalf estimates, for example, that if there were no unions, the gap between male and female wages would be three percentage points wider.
The real battles to come, however, are likely to be over the structure, incentive schemes and economics of public services. The Government's desire to use market mechanisms and private provision in the NHS will certainly mean trouble ahead. Stir in a good dose of downsizing as the pressure grows on tax-funded institutions of all kinds to become leaner and more efficient, and a potentially explosive cocktail is in the making.
Of course, a handful of strikes is thin evidence for a remilitarisation of the workforce. But it seems highly likely that unionised public-service professionals will use the withdrawal of their own labour as a weapon in the broader battles over the shape of public-service provision, as well as to defend their own position. To adapt a phrase from Gordon Brown, 21st-century striking will be picketing for a purpose.
But the renewal of the strike option can make an impact only if the unions succeed in reframing their mission and purpose in the broader social and political terms described by Flanders. Typically, unions have been seen as among the least likely of organisations to change - as dinosaurs waiting for their inevitable extinction.
Labour hero Ernest Bevin said: 'The most conservative man in this world is the British trade unionist when you want to change him.' But it looks as if unions may well be changing in ways that could yet bring the cry 'everybody out!' back to at least some British workplaces. Recent events show that it is certainly too early to consign strike action to the museum of industrial history.
Richard Reeves is director of Intelligence Agency, an ideas consultancy; e-mail: firstname.lastname@example.org.