Last Friday morning it all seemed so clear. I was listening to Derek Simpson, leader of the Unite union, talking about the unofficial strike in Lincolnshire. “Some of these companies,” he said, “are coming in and saying they will exclusively debar UK workers, that they will not consider UK workers under any circumstances.” So, though the strike was nothing to do with him (being illegal and all), he could “understand the moral indignation” of Brits who had the necessary skills but were now forced to be unemployed and “watch foreign workers who have more privilege because they're not debarred from these contracts”.

His interviewer then asked Mr Simpson whether he knew for sure that the Lindsey workers had been debarred. “Oh, I think the evidence is there,” he replied. “Some of these contractors have been blatant enough to say that to our local officials.” He was pressed: to say what? “That they will not consider UK workers.”

Mr Simpson's widely repeated speculation was that the contract at the Lindsey oil refinery had been subcontracted to a company using mostly Italian labour purely for cost reasons. “We're questioning why they can bring additional workers from overseas with additional costs of transport and accommodation. It's hard to believe that is possible unless they're paying lower rates.”

That was the incendiary essence of it. Good local workers were being actively - almost callously - discriminated against so that cheap foreign labour could be drafted in to do the job instead. The balloon went up, and has stayed up. Sympathy strikes (also unofficial and illegal) spread even faster than the snow. Back at Lindsey, Kenny Ward, the plant's Unite shop steward, told the crowds over the weekend: “I'm a victim, you are a victim, there are thousands in this country who are victims of this discrimination, this victimisation of the British worker.”

Given such emotionalism, that the BNP vaulted on to this bandwagon is no shock and, of itself, is no repudiation of Mr Simpson's and Mr Ward's case. The speed with which sympathy action broke out, and the plans for a national demonstration along the theme of “British Jobs for British Workers”, seem, if anything, to confirm their arguments.

The trouble was that the case they were making appears not to have been quite true. It isn't just that the companies involved have pointed out that more than a thousand British workers are already employed at Lindsey, or that the subcontractors claim that the foreign workers on the construction project are paid full rates and enjoy the same conditions and have been employed because of the specific skills they have as a team. Those companies could, of course, be lying.

But I also called the Unite press office and asked them to supply any details they could of Mr Simpson's specific allegation that his officials had been told by the “blatant” subcontractors that they would not employ UK workers. A few minutes later a nice chap rang. He wasn't sure that Mr Simpson had been referring to Lindsey specifically, but there were other situations where this might have happened. He'd ring round and call me back. The call never came.

So, no one in Lindsey had been told that British workers were debarred and indeed there was no evidence that they were debarred. And the foreigners - EU nationals - on the specific project may well not represent any kind of attempt to cut the costs of hiring workers. So what on earth was this about?

Here's a clue. Also yesterday another union bigwig, Paul Kenny, of the GMB, described the “root cause” of the rash of wildcat stoppages as being “discrimination against British workers”. Mr Kenny cited in evidence personal conversations with companies who had told him that they “cannot instruct these firms [ie, subcontractors] to employ British workers” because of EU law. In other words, the lack of the ability of companies to discriminate against foreign workers was really the issue for Mr Kenny, not discrimination against British ones. What he evidently wanted was the right to employ British workers - members one presumes of British unions - in preference to EU ones.

So when the TUC General Secretary, Brendan Barber, piously and nervously clarified that the unions thought that “anger should be directed at employers, not the Italian workers”, he was in danger of misunderstanding the nature of the argument his own side had mounted.

Facts notwithstanding, the Lindsey strike has brought a colonic flush of sentiment about how entitled the British are to their rage. Some of the country's leading commentators have enjoyed one of their occasional joyous moments of getting down and dirty with the workers. There has been nonsense about the slow patience of the English (“but when roused to ire... blah, blah”), about how we should be more like the French, whose utterly pointless national strike paralysed that country on Thursday, about how the ordinary man should blame the bankers, the EU, the Government, the quangocrats or anyone else.

From the Right and the Left the target was globalisation. Jon Cruddas, MP for Dagenham and the unofficial leader of Labour's centre Left lamented: “Britain is a country that no longer owns the productive processes that create its wealth. Crucial economic sectors have been handed over to unaccountable foreign ownership.” Note here the linking of “foreign” with “unaccountable”, as though the good old failing domestic companies used to invite us to vote on their expansion or contraction policies. Letting EU workers undercut British ones (as has certainly sometimes happened) had been, according to Mr Cruddas, “a race to the bottom”. Albeit one that, until recently, left us able to enjoy low unemployment and hugely expanded public services. You must have noticed the schools, John? Even in Dagenham.

On Sunday the Government, in the shape of Alan Johnson, panicked on the BBC. Well, sometimes you have to. Yesterday, in the shape of Lord Mandelson, it un-panicked again, also on the BBC. Well, usually that's better. John Humphrys pressed the case of the (hypothetical) Sunderland worker who is underwhelmed by the bigger argument against protectionism in jobs, or by hundreds of thousands of Britons occupying posts in other EU countries that could also, presumably at a pinch, be filled by locals.

The answer, of course, is that temporarily satisfying Kenny Ward (or Carlo Wardi or Karl Wardowski) would lead to a stupid game of International Beggar My Neighbour, in which, far from guaranteeing jobs for British workers, or jobs for Italian workers, we would end up with even fewer jobs for both. Someone needs to tell them that truth up in Lincolnshire, because I don't think Derek Simpson will.

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