By trade, Mr Gordon Brown is more a Labour historian than he is an economist. Accordingly, the sad story of Mr Peter Mandelson's maternal grandfather, Herbert Morrison, will already be familiar to him. Others may need to be reminded of it. In the war, he was one of the pillars of Winston Churchill's Coalition government. As Home Secretary, he was as well-known - and, by and large, as highly regarded - as those other solid citizens Ernest Bevin, Stafford Cripps and the party leader himself, CR Attlee.
When Labour unexpectedly won the 1945 election, there was even a chance that Morrison might have become prime minister instead of Attlee. The leftist savant Harold Laski and Morrison's lady friend Ellen Wilkinson (the Barbara Castle of her day) urged him to call for a meeting of the parliamentary party to elect a new leader. Their reason was that Attlee had been chosen 10 years before by fewer and different MPs and that the new lot deserved to be able to make a fresh choice.
This was not an altogether implausible argument. In different circumstances, admittedly, Bonar Law had insisted on being elected leader of the Tory party before becoming Prime Minister in 1922 - much to the annoyance of George V. Morrison might well have beaten Attlee in 1945. But there was no opportunity to put it to the test. Bevin advised: "You get down to the Palace quick, Clem." And Attlee duly became Prime Minister, as he remained till 1951, with four more years after that as party leader.
In the postwar government, Morrison was Lord President of the Council and Leader of the House. As such, he pushed through Labour's huge programme of nationalisation, even though he was himself by inclination an early revisionist. "Socialism is what a Labour government does," he is supposed to have said once, though I have never succeeded in tracking down the quotation. If Attlee had retired at any time in 1945-51, there is little doubt that Morrison would have succeeded him.
But Attlee went on, as Mr Tony Blair is going on. Indeed, according to Cherie, Mrs Blair, he is going on and on, just as Mrs (as she then was) Margaret Thatcher was going to go on and on and on, as she boasted to Mr Robin Oakley, then of the BBC, shortly before the Great Fall.
Attlee not only went on. In March 1951 he appointed Morrison Foreign Secretary to succeed the dying Bevin. In retrospect he regretted this decision. He said that he should have appointed, not Aneurin Bevan (though if he had done so he might have avoided Bevan's resignation in April), but another Welshman from further west, Jim Griffiths. At all events, Morrison was a disaster. This was not entirely his own fault, for he had the Iranian (then called the Persian) oil crisis to deal with. His reputation never recovered from his spell at the Foreign Office.
Even so, he would probably have succeeded Attlee if the leader had gone in the early 1950s. When he did finally depart, in 1955, Hugh Gaitskell was reluctant to enter the contest at first because Morrison was still regarded as the champion of the Labour right against Bevan. In the event the three of them all stood, Bevan, Gaitskell and Morrison. Morrison even went so far as to order a new suit from the Woolwich Co-op tailor, who quite rightly gave him preferential rates. In the event he came bottom of the poll with a pitiable 40 votes. Gaitskell was elected leader with an absolute majority, and Morrison lived a further 10 sad years to die at the age of 77.
There are several differences between him and Mr Brown. Morrison was surrounded by his equals or, as some would say, his superiors: in the war years, by Bevin, Cripps and Hugh Dalton and, later, by Bevan and Gaitskell. Mr Brown, by contrast, stands out not so much because of his own merits (considerable though these are) as because of the flatness of the surrounding countryside. The danger is not that some other rival will creep up on him, like a thief in the night, as Gaitskell overtook Morrison. It is, rather, that he will inherit an indebted or even an insolvent estate, much as Mr John Major took over an embittered, argumentative and confused party from Lady Thatcher.
The dangers for Mr Brown may not be identical but they are none the less similar. The worst, the unthinkable, outcome is that he may not (to begin with, at any rate) be Prime Minister at all but Leader of Opposition instead. The wisdom of the wise is, I know, that Labour will go on to win the next election whatever happens. I am not so sure.
There is the possibility either of a complete loss of office or of a continuation of Labour rule by a minority government. Mr Brown would certainly not want to to arrive at an arrangement with Mr Charles Kennedy. But would he even be prepared to try it out? Or would he prefer to run, say, the IMF? Then there are all these European referendums to think about. Mr Brown controls the referendum on the euro, irrespective of whether he is Chancellor or Prime Minister. Not so the referendum on the European constitution. Does Mr Blair fight for it as Prime Minister, or retire beforehand and leave it for Mr Brown to sort out? Either way, it is not a tempting prospect for Mr Brown.
So it is not to be wondered at if Mr Brown has been a little on the touchy side over the past week. It started with the news that Mr Derek Scott, a former economic adviser at No 10, had written a book mentioning the rows between Mr Brown and Mr Blair in a disobliging manner. Mr Brown, or his acolytes, then proceeded to blame not Mr Scott but No 10. The spokeswoman there then turned on Mr Scott, accusing him of stating that which was not the case, and using in the process a legally incandescent word. I shall not reproduce it here because (unlike the BBC before the Hutton report) I happen to know that you cannot justify defamation by saying you are only repeating what someone else has said.
Mr Brown's departing man-of-business, Mr Ed Balls, who is to be a Labour candidate, then repeated the libel against Mr Scott on Newsnight, for broadcast words are classed as libel rather than as slander. Far be it from me to urge anyone to go off to the Queen's Bench Division with a claim for libel. It is a bit like a playground bully setting two small boys on each other. Besides, it is an even quicker way of losing money than owning a racehorse. Nevertheless, it does seem to me that Mr Scott has been defamed, both by Mr Balls and by No 10, whose spokesfolk do not enjoy the protection of qualified privilege in any way at all. It only goes to show where frustrated ambition can lead.