Seldom has one industrial dispute said so much about our society as the now concluded issue of the future of the Grangemouth refinery. Unite has reached an agreement with the owner, Ineos, which will guarantee the future of skilled and well-paid work at Grangemouth well into the future. In essence, it is not different from the difficult discussions my union and others have had with many employers during the current banking slump, working to keep jobs alive while adapting to the position some companies find themselves in.

I went to Scotland last week to save those 800 jobs and keep a vital national asset open in the face of a real threat of closure from the employer. But I applaud our team on the spot for also fighting to maintain the pay and conditions of the people who pay their membership subscriptions. That is what trade unions do.

And I am delighted that at a mass meeting of Unite members on the Grangemouth site on Monday, unanimous support for and understanding of the union's role was expressed. These are the people I answer to, not Rupert Murdoch's leader writers.

But there are far larger issues raised even than the future of one plant. Because what has happened at Grangemouth shines a vivid light on the nature of power in our society today.

The central message is clear – the rights of private ownership are unchallengeable, even in a vital economic sector like energy, and the ability of the capitalist to hold workforce and community to ransom is undiluted. It is hard to blame Ineos or any company for exercising the power we have for too long been happy to let them have.

This is the bitter harvest of years of laws designed to weaken trade unionism, of neoliberal dogma that rules public ownership out of court, and of rule by a smug elite whose greatest achievement is not economic or social, but to have paralysed the will of politicians.

And if you want to know what the consequences can be of standing out against this consensus, consider what has happened to Stevie Deans, the union branch secretary who resigned from Ineos this week, having been targeted by management as the "enemy within".

Stevie's crimes appear to have been twofold. He looked after the workers at Grangemouth – all too effectively for some people's tastes. And he took on vested interests in the political field too, trying to involve more ordinary people in democratic life.

For this he has had to leave his job, he has been traduced in the press, he has had his private correspondence placed in the public domain, been the subject of police investigations and more.

Now there is a demand for a new investigation into the whole issue. The published material I have seen shows no basis for reopening the Falkirk wound. Remember that the candidate Unite supported has withdrawn from the selection race, and none of the members recruited – quite legitimately under the rules as they were – will have a vote when it comes to choosing Labour's candidate.

And Labour is already reviewing selection procedures, a process which I hope will create a level playing field, something which has been notably absent in the recent Lord Sainsbury-funded, grace-and-favour New Labour past.

For all the hyperventilating in the media, nothing has been shown that changes any of that. Already Labour and the police have given Unite a clean bill of health – if Labour in Falkirk is to move on, then I think a fresh inquiry would be of less help than the overdue resignation of its sitting MP, Eric Joyce, whose misconduct set this whole sequence of events in train.

Just as Unite has nothing to apologise for in becoming a more active participant in the life of the party we created, rather than just a cheque-writing machine, nor will we apologise for sticking up for our members.

Today we are in the midst of something all too familiar to those of us who remember the 1970s and 1980s – a hysterical smear campaign directed against trade unions because we represent the only real organised challenge in society to the values and views of our bankrupt establishment.

At a time of economic slump and people casting around for an alternative, that elite will only feel secure when they can dance on the grave of trade unionism. I am afraid they will just have to get used to sleepless nights instead.

So we are witnessing a witch-hunt against Unite and Stevie Deans. Ineos's PR advisers, the charming people at corporate reputation specialists MediaZoo, boast of their capacity to help companies deal with "crisis situations including … fatal accidents and child labour", according to their website. In a "crisis situation" Unite's priority is not protecting the reputations of the powerful, but protecting the victims of the exercise of their power. That power inequality has been on brutal display this week, and Labour politicians above all need to pay attention.

Len McCluskey is general secretary of Unite