Ministers and local government employers may be spitting blood, but behind the fire strikes there lies an unpalatable truth for politicians: Andy Gilchrist, the Fire Brigades Union leader, has a greater mandate for his activities than they have for theirs. Who supports the privatisation of air traffic control and the London Underground or, for that matter, telling the FBU membership its pay claim is "ludicrous"? But there's not much doubt that Gilchrist's members support the strike.
Think back to last year's general election. The turnout, at under 60 per cent, was the lowest since 1918. In local elections, the figure is even worse, at barely 30 per cent, and sometimes lower.
Turnout in elections for union general secretaries are not brilliant, either, particularly in the larger, more general ones. For example, Derek Simpson, general secretary of the AEEU engineering union, now part of the Amicus manufacturing combine, was elected on a 25 per cent turnout. But in the smaller, more focused unions, many of them now led by "militants", the turnouts are healthier, and certainly compare favourably with the local authorities whose appointees negotiate with the firefighters. Mick Rix, general secretary of the train drivers' union Aslef, won on a 55 per cent turnout, Andy Gilchrist on 45 per cent. For Bob Crow's election at the RMT transport union, just over a third of the members voted.
In strike ballots, unions frequently record turnouts of between 60 per cent and 80 per cent. RMT strikes at Arriva saw 69 per cent of those balloted return their papers, with 93 per cent agreeing to walk out. The FBU strike saw 87.6 per cent vote for a strike on a turnout of 83 per cent.
Then there are ballots for union recognition in the workplace. By law, the turnout has to be above 40 per cent if the result is to be valid. In fact, it is often well above this, and in some cases double. In general, involvement is more impressive than in, say, the Scottish and Welsh referendums on devolution, where turnout struggled to reach 60 per cent and 50 per cent respectively.
Laws designed to curb union power have, by introducing so many balloting requirements, actually increased the unions' democratic legitimacy. While Labour often ignores the views of its own MPs, unions can lay claim to being the last true democrats. The RMT Underground staff who refuse to work during the fire strike on grounds of safety may be sailing perilously close to secondary action. But for the most part, unions, if accused by either the government or the opposition of acting outrageously, can simply reply that "we're obeying the rules you set".
This is one reason why comparisons with the 1970s are wrong. Industry was then riddled with closed shops, flying pickets and unofficial action - all thoroughly undemocratic.
A far better comparison is with the 1910s, the decade when modern trade unionism was born. Then as now, labour was in demand: unemployment remained below 3.3 per cent between 1914 and 1919. Union status and membership grew: there were four million union members in 1914 and nearly eight million in 1919. Days lost to strikes soared from 9.3 million in 1914 to 36 million in 1919.
Could this decade see a similar trend? Don't rule it out. After years of steep decline since the 1970s (to a level well below 1919), trade union membership is rising again. So are strikes. Fewer than 500,000 days were lost in 2000; for the first eight months of this year alone, the figure is 882,000.
But these are not in any sense political strikes. As in the 1910s, union campaigns are now tightly industrial, concerned with pay, conditions and so on. If you ask the "militants" what unions are for, they will point back to the beginning. Read out Sidney Webb's answer in 1920 - "a continuous association of wage-earners for the purpose of maintaining or improving the conditions of their working lives" - and they will more or less agree. This is the ticket they stood on in their leadership campaigns, often against opponents who were more interested in talking to ministers and extending their influence within the Labour establishment. They did not pretend that they could steer ministers on social and welfare policies, as their predecessors did with their "social contract" in the 1970s. They simply claimed that they could negotiate better wages and conditions for their members than their predecessors could.
Their politics - and their unions' relationships with political parties - are of secondary importance. Gilchrist is a Labour man. Rix is, but wasn't. Crow, a former member of the "Scargillite" Socialist Labour Party, is now unattached. The "militant" Mark Serwotka of PCS, the civil service union, supports the Socialist Alliance. Simpson - horror of horrors - is a former communist (like many in the Labour cabinet, as it happens).
None of this is now of great importance. Simpson says: "I was a communist because everyone in Sheffield at that time [the 1960s and 1970s] was a communist. You didn't really think about it." An ally of Crow - who is variously branded as a "Trot", a "revolutionary" and a "headbanger" - says: "Bob is not a Labour member. But that doesn't mean Labour are not better than the alternatives. Equally, just because we have a Labour government does not mean we have to shut up and be good."
All but one of today's "militants" head unions either in the public sector or in public services that have a close relationship to the government. The driving force for action in areas where the government is either directly or indirectly the employer and/or the funder, this is why they so vehemently deny that their strikes are politically motivated, as Tony Blair suggested (but later retracted) in a press briefing. The point they make again and again is that, according to official statistics, public sector pay has risen by only 3.8 per cent year on year between 1997 and today. Compare that with the two-year, 24 per cent rise for the CBI head, Digby Jones.
In the firefighters' dispute, one local government employer has said (he didn't want to be named) that "it's about who runs the Fire Service". The echoes of Edward Heath asking "who runs the country?" when he appealed to the voters against the miners in 1974 are conscious. And this is indeed a dispute partly about control. But the issue is control of working conditions. The firefighters' union won't accept the proposals for "modernisation" outlined in the Bain report. Why? Because they believe they would cede wholesale control of their working practices to an appointed agency. It is a concern as old as trade unionism, dating back to the syndicalists and "industrial democrats" of the 1910s and 1920s. Today's union leaders resist being called syndicalists. But their agenda rings those bells.
The FBU's demands to retain control may seem outrageous, a 40 per cent claim too much. Shift patterns may have to change; jobs may have to go. But however this and future public sector disputes end, ministers and local authorities should understand that they are being attacked because union leaders think they are bad employers, not because unions want revolution. And in such democratic bodies, it's obvious when the members agree.
Oliver Morgan is industrial editor of the Observer