Managers, councillors and unions in Glasgow will be drawing breath in the next couple of days as they meet for renewed talks after two days of strikes by thousands of women over equal pay.
The city council's leaders could be forgiven for wondering what hit them as the story made national headlines and news bulletins.
Campaigns of industrial action in recent years have all too often seemed to peter out as it became obvious that union leaders were not well supported by their own members, but this two-day strike by more than 8,000 cleaners, care workers, school support staff and other generally low-paid women was by all reports solid.
As the action took hold, it also became clear that they had backing from other council workers and many in the general population. 'The city of Glasgow supports the women,' as one union leader told LocalGov.
Union offices reported being inundated with calls in support while parking attendants, refuse workers and staff at iconic city centre institutions such as the Kelvingrove Art Gallery and Museum refused to cross picket lines.
SNP council leader Susan Aitken appeared rattled as she repeatedly pledged support for the strikers' case – while condemning the action as unnecessary and dangerous – and promised it could all be sorted out.
On the union side it is very much a case of 'we'll believe it when we see it'. They argue that was no firm offer to settle the dispute in more than 20 meetings with management since the Court of Sessions found against the existing pay and grading structure last November.
And they say that 12 years after the council ushered in a package meant to rectify the pay anomalies, and a ballot for industrial action in September, the council could not claim they didn't see it coming.
The council, however, rejects the unions' claims. It says the union side has been inconsistent and unwilling to make progress. There has been no clear demand on which council officers could base a proposed settlement.
It is not helped by the fact that the women's case is far from simple. There are three unions involved, Unison, the GMB and Unite. All three are representing their members as collective groups in the traditional trade union way. But Unison and the GMB are also representing thousands of individual members who have made specific claims.
Added to that, a third party organisation, Action4Equality Scotland, a private company specialising in equal pay claims, represents several thousand individual legal cases being brought by women, including many who are members of the unions.
The council specifically rejects the claim that no progress has been made. It says it agreed to the unions' demand for an arms-length company, Cordia, which employed most of the woman care workers, cleaners and caters, back in-house and this happened last month.
It says it agreed that the women claiming equal pay would be recompensed. It agreed to abandon the pay and grading structure adopted 12 years ago which has been at the base of the long-running dispute, and agreed not to go down the legal route of appealing the Court of Sessions judgment.
The council argues that the talks were progressing and there was no logical reason for calling the strike which shut all the city's primary schools, halted refuse collection and put many vulnerable people at risk.
It is difficult to untangle the web of claim and counter claim being made in this serious dispute. There are many women involved and large amounts of money at stake. Any new pay and grading structure will have an impact for years to come.
But as talks resume following one of the most strongly supported pieces of industrial action in modern times, it can only be hoped that with goodwill on both sides the outlines of a settlement will emerge quickly. No-one wants it to go on for another 12 years.