When privateering energy companies have raised prices so much that David Cameron advises people to switch suppliers - apparently they don't teach pupils about cartels at Eton - and a Downing Street spokesperson suggests wearing jumpers it is a sign of an energy crisis.

In the immediate case it is a crisis relating to people's ability to pay and the privateers' determination to maintain high profit levels come what may.

But there is a wider issue relating to energy supply. Obviously private energy companies can't be expected to invest a great deal of money in making sure the network can meet demand, so media reports indicate that depending on how cold the winter is there may be power cuts ahead.

There is also something of a furore over George Osborne's plans to involve Chinese investment in the upgrading of the nuclear power station at Hinckley Point. Quite why is a little unclear since much of the rest of the energy industry is in foreign hands too.

So far so bad - but there is something missing from this account which you can't glean from a reading of the financial pages of the more serious newspapers. What is absent is any sense of history.

It is 40 years since the energy crisis of 1973 and that ushered in an era which we remain in today.

The Yom Kippur war of October 1973 between Egypt and Israel led to a restriction of oil supplies by Middle Eastern producers and a significant rise in oil prices. It was this more than anything that ended the post-1945 era of cheap and plentiful energy.

Then on November 12 1973 the National Union of Mineworkers started an overtime ban in pursuit of a wage claim outside of the then Tory government's "phase three" incomes policy.

Combined with the restrictions on oil the impact on energy supplies was significant.

The sense of political and social crisis that began to develop in that British autumn of 40 years ago is difficult to grasp for those not alive at the time or too young to recall it.

The Labour opposition was split on the miners' action. Labour leader Harold Wilson reported to a Labour Party NEC meeting on November 28 that talks between the miners and the Coal Board had broken down.

Tony Benn recorded in his diary that he pushed a policy of supporting and trusting the miners. Right-winger Anthony Crosland, by contrast, argued that Labour should not back the miners.

By December 7 Benn was recording his "there is a great sense of crisis everywhere" speech.

Indeed such was the depth of the crisis that on December 13 Tory premier Ted Heath announced that industry would move to a three-day week from January 1 1974. Power cuts were widespread for business and residential users.

The crisis got even worse after Heath's announcement, perhaps inevitably. Two days before Christmas on December 23 the oil price doubled.

Tory minister John Davies told his family: "We must enjoy this Christmas. It may be our last one."

We can see immediately why it is that Cameron and the largely right-wing media will be very unlikely to mention the anniversary of the start of the NUM overtime ban, even though it is one of the more significant dates in post-1945 British history.

The short-term outcome of these events is perhaps better known. Ted Heath called a general election in February 1974 on who governed Britain, the Tories or the unions.

The voters decided it was the latter and Labour returned to office.