Sean O'Grady: The unfortunate fall guy for Gordon Brown

Alistair Darling always reminds me of one of those contestants on The Apprentice, the type who are sensible, who never do anything wrong and whose team leader regularly lets them down – but who you know is going to get fired by Sir Alan Sugar. There's plenty that has gone wrong at the Treasury since Mr Darling took over a year ago, but not much that can be blamed directly on him, poor man. Losing the data discs? Not a single case of fraud has been reported. Some scandal. The credit crunch? The inevitable corollary of a credit boom, left undisturbed to run its delusional course by former chancellor Gordon Brown. Northern Rock? A consequence of the credit crunch, qv. The abolition of the 10p rate and other various botched tax rises? Mostly pre-announced in Mr Brown's Budgets. The collapse of the Government's fiscal rules? Mr Brown spent too much, recklessly so during the boom, a time when he should have been building up the public finances "for a rainy day". Inflation way off target? Blame the Chinese for consuming all that oil. Besides, it's the Bank of England's job to keep inflation down.

So what's Mr Darling guilty of, exactly? Nothing – but that won't help him survive. First, Mr Darling happens to be sitting in the wrong place at the wrong time. It's an old story. A Chancellor faithfully carries out the wishes of the Prime Minister but when the policies goes disastrously wrong it is he, rather than the PM, who is sacrificed. It happened to Norman Lamont, forcibly removed from the Treasury in 1993 by John Major not long after sterling was humiliatingly ejected from the ERM, a policy Lamont was never much keen on anyway and was very much Major's own. It happened in 1967 to James Callaghan, who lost his job after an earlier devaluation of sterling, which was a policy he agreed with, but which was nonetheless dictated by his Prime Minister, Harold Wilson.

Wilson, so much like Major, simply carried on as if nothing had happened. Both beleaguered Prime Ministers recruited better, cleverer Chancellors in place of the sacked ones – Roy Jenkins and Ken Clarke – and went on to lose the subsequent general elections: Nemesis delayed but not averted.

Mr Brown could all too easily lumber Mr Darling with the blame for the failure of his policies. Unfair, but a definite option for Number 10.

Second, Mr Darling has no "following", no fan club, no political base. You get the impression that he was appointed by the desperately insecure Mr Brown on what might be termed the "David Brent" (as in The Office) principle of recruitment: "Be careful because there is always someone ready to step into your shoes and do your job better than you do it."

Darling will probably be another footnote Chancellor, like Anthony Barber (Heath's man at the Treasury from 1970 to 1974, and a disaster because he couldn't stand up to his boss) or Derick Heathcoat-Amory (Macmillan's forgotten economic chief from 1958 to 1960). Darling is already perceived as more puppet than master. Most Chancellors, like Mr Brown, are "big beasts", obvious candidates for the top job. A few make it to Number 10, the cohort split between those who exceeded expectations when they arrived (Macmillan, Lloyd George, Winston Churchill and Callaghan) and the underperformers (Neville Chamberlain, Major and, as we now know, Gordon Brown). Hugh Gaitskell, Attlee's last Chancellor, got to lead his party, while the bunch who nearly got to the top is almost as distinguished – Rab Butler in the 1950s, Reggie Maudling and Roy Jenkins in the 1960s, Iain Macleod and Denis Healey in the 1970s, and Ken Clarke a decade ago. A few, such as Hugh Dalton and Stafford Cripps in the 1940s, and Nigel Lawson and Geoffrey Howe in the 1980s, weren't taken too seriously as potential leaders, but were still substantial. Most had formidable intellects. All were pretty unsackable. Mr Darling is less well endowed than any of them. He is eminently sackable.

Third, Mr Darling has rivals. With weary inevitability we are hearing the suggestion that Ed Balls, who is currently kicking his heels as Schools Secretary, will replace Mr Darling in a summer reshuffle. It may not be long before Andy Burnham's and James Purnell's names also gain currency, alongside Alan Johnson and Jack Straw. They are all plausible when placed next to Mr Darling.

The greatest Chancellors drive their government's domestic agenda forward, using the Treasury as their engine – a very powerful machine in the right hands. Brown himself showed what could be done, though the legacy was unhappy. History shows that a government can be re-energised from Number 11 as well as Number 10, even if it cannot be saved. In their different ways Maudling, Jenkins, Healey and Clarke all put vigour into the defence of the doomed governments they served. Whatever the qualities of his highly intelligent Edinburgh lawyer, Mr Darling is not up to that task. Then again, who is?

s.ogrady@independent.co.uk