A week ago, hardly anyone outside the petrochemical industry had heard of Jim Ratcliffe. He is now at the centre of a trade dispute that has shut down the Grangemouth refinery and the Forties pipeline, threatening shortages of petrol and gas. This may be the most important strike politically for a generation. It certainly threatens government popularity, waning and at its lowest point for 20 years.

It would be easy to portray Mr Ratcliffe as either the hero or the villain of this story; he is probably something of both. His private company, Ineos, has created a new British petrochemicals industry out of the undermanaged relics of the industry of the 1980s and 1990s. Ineos has invested $15 billion on purchases, and further billions in plant. It is now the third largest petrochemical company in the world.

Ineos now makes sales of $25 billion a year, and is probably the largest producer of plastics in Europe. The company has the reputation of being very efficiently managed, with strong delegation to its operating divisions and tight control of costs. Mr Ratcliffe has saved a declining British industry and thousands of jobs. That is the heroic side of the picture.

There are other aspects that will be less popular. Normally, when there is a big trade dispute, the trade unions are blamed for unreasonable militancy. In this dispute, Unite, the main union involved, has behaved with some moderation, historically speaking. The dispute is about pensions. The Ineos management want to introduce new, but less generous, terms for new recruits.

What the management wants is not in itself unreasonable, since the old system of final-salary pensions has largely been destroyed in the private sector and the old Grangemouth pensions date from the days of BP, which was a wealthy oil company. However, pensions were no larger than the norm for the oil industry and public sympathy is now likely to favour trade unionists defending the pension rights of their members, even when strikes affect consumers. Trade unions are thought to be entitled to defend workers' pensions by strike action.

Pensions are politically sensitive issues, particularly for Gordon Brown. His first action as Chancellor, as long ago as 1997, was to take some £5 billion a year of tax from the pension funds. That stealth tax led to the old final-salary system being widely discarded as too expensive. Mr Brown caused the British pensions crisis that lies behind the Grangemouth dispute. He is more to blame than Unite or Ineos.

The Ineos case is also unpopular because Ineos is secretive and Mr Radcliffe has become extremely rich, a multibillionaire. When Ineos is described as a “private equity” business, the senior managers protest that it is only an ordinary petrochemical company. Yet it has been financed by borrowing on a private-equity scale: it has made private-equity-type sales as well as acquisitions; it is privately owned. It also resembles other private-equity companies in its failure to disclose to the public information that would be legally required from public companies.

All the big oil companies, and particularly BP, understand that they are in the politics business as well as the oil business. Oil is always political. Ineos is also in the politics business, whether it likes it or not. When Ineos suffers a strike at Grangemouth, oil and gas prices are likely to rise; oil and gas may become unavailable over wide areas of Britain. In this case, the whole of Scotland and much of the North of England are liable to be affected to some extent. Such a crisis of supply affects millions; this is politics for the unions; it is politics for Ineos; it is politics for the Government.

No doubt Mr Radcliffe would prefer to reconstruct his acquisitions in privacy, but Ineos has become too big for that; his decisions now have an impact on a broader community. The privacy of private-equity companies is undoubtedly a commercial advantage, so long as they are small, and their decisions have only a limited impact on the general public. However, the success of Ineos means that it now has to face public accountability; for them, the age of privacy is passed.

Mr Radcliffe has come under the spotlight, whether he likes it or not; Unite will be put under the spotlight as well; but the real damage may be done to Mr Brown.

Earlier trade union disputes led to the defeat of Wilson in 1970, of Heath in 1974 and of Callaghan in 1979. From any government's point of view, a big strike that affects the broad public is a serious political threat. Apart from the actual damage done by such strikes, they show up the weakness of government. Prime ministers who cannot stop strikes are bound to look impotent.

Weakness and indecision have already sullied Mr Brown's early image. He was indecisive over the decision to call or not to call an early election, and over the credit crisis and Northern Rock. He has been forced to surrender to Frank Field over the 10p tax band. He is more responsible than anyone else for the destruction of the final-salary system, which led to the Grangemouth strike. No wonder he has gained an image of indecision, damaging to himself and his party.

Intellectually, Mr Brown may be the ablest man on the Labour front bench; he has an analytical penetration far beyond his predecessor, Tony Blair. But the primary quality of a prime minister is not analytical, but the ability to take decisions.

Gordon Brown has, ridiculously, been compared to Stalin. He is no Stalin. He lacks the grip of a leader.

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