Gordon Brown is no exception. The Labour leader's much-hyped political fightback begins this week with action to kickstart the housing market, the energy crisis and a rare Cabinet away-day to the provinces.

It is also the week when the PM is supposed to show some courage – the recurring theme of his literary offerings – and implement a wide-ranging reshuffle that would remove the political "dead wood" from positions of influence.

That's what his spin-doctors have been saying. However, it appears that the courage shown by this country's triumphant Olympians in Beijing has not rubbed off on Brown. The reshuffle may now be delayed until after this month's party conference.

This indecisiveness means that the country faces the absurd prospect of Ministers unveiling their departmental priorities at the conference – a key plank of the relaunch – in the knowledge that they will moved sideways, or handed their P45s, shortly afterwards. So much for continuity.

It also begs the question whether Brown's authority has been so weakened by Foreign Secretary David Miliband's pre-emptive strike for the Labour leadership – and Chancellor Alistair Darling's refreshing honesty over the economy – that he may not survive his own reshuffle.

The PM would have sacked Miliband on the spot for disloyalty if he was in charge of his own destiny. The same is true of Darling, whose economic prognosis undermines the very foundations of Brown's defence; namely that the nation's finances are safe in his hands. How can it be if his Chancellor says that Britain is heading for its worst slump in 60 years?

If Brown leaves both men in post, he will be accused of weakness. Yet if he tries to sack Darling and Miliband – or move them sideways in a possible job swap – he might face a potential mutiny that could have the power to put his premiership out of its misery. They are unlikely to go quietly, given their summer interventions.

In other words, Brown is in a "lose-lose" situation. But that, in many respects, is the outcome of all reshuffles. They are, effectively, admissions of failure. They are only held because a Minister has been forced to resign – invariably because of scandal – or that they have to be sacked because they have not lived up to the PM's expectations.

The only time when a Prime Minister has a free rein is after an election triumph – or when a PM comes to power midway through Parliament, as happened with Brown last summer.

That is why Brown's soul-searching provides stark evidence of his own failure to pick a team of sufficient substance and stature to govern the country until the next election.

Yet Prime Ministers constantly ignore this reality in the mistaken belief that reshuffles can restore their fortunes; the most glarinig example being the unfortunate John Reid who held seven different Cabinet posts in eight years before he stepped down from the Home Office when Brown succeeded Tony Blair.

A successful company would not ask one of its leading directors to perform seven key roles in such a short timeframe, so why should the Government be any different?

As Douglas Hurd, the former Foreign Secretary and Tory grandee, shrewdly advised Brown at the start of his premiership, constant change undermines the political process; hence why the PM needed to pick a successful team and then give them the time, and scope, to fulfil their remit without the threat of a reshuffle.

And, as a distinguished historian, Lord Hurd of Westwell is acutely aware that history is littered with examples of Prime Ministers paying the price for botched reshuffles.

Most famously of all, Harold Macmillan sacked seven Cabinet members in the 1962 "night of the long knives". It was a desperate attempt to restore the fortunes of a tired Conservative Party after a decade in power.

It did not work. The following year saw Macmillan resign on health grounds, and the Tories subsequently lose the1964 election to a charismatic Harold Wilson.

And, as Norman – now Lord Fowler – observes in his new book A Political Suicide: The Conservatives' voyage into the wilderness, Margaret Thatcher's reshuffle in July 1989 was a shake-up driven by panic that fatally undermined confidence in her leadership.

This saw Geoffrey Howe, the Foreign Secretary, move to be Leader of the Commons, and a hitherto unknown John Major promoted to the Foreign Office – much to the annoyance of Nigel Lawson, the then Chancellor, who had coveted the job.

With Hurd's position as Home Secretary also offered as a consolation prize to the vanquished, Fowler observed: "The irony of the reshuffle was that it satisfied almost no one at the top of government.

"The July reshuffle, intended to show the government fighting back, had been transformed into a political disaster... and Howe was wondering whether he should have refused the new job and resigned."

Howe did accept his new job, but his brooding, and subsequent resignation in the autumn of 1990, precipitated a tearful end to Thatcher's reign.

It was the same in May 2006 when Tony Blair tried to shore up his own faltering position with a raft of changes that, infamously, saw Margaret Beckett promoted to the Foreign Office.

This change was portrayed as an act of decisiveness. It was nothing of the sort. It was a desperate attempt by Blair to cling on to power and, within weeks, he was having to announce outside a school that he would resign in the summer of 2007 after serving 10 years as Prime Minister. The humiliation was complete.

However, there is one common thread that links the fateful Macmillan, Thatcher and Blair reshuffles, and it is this. Their respective parties had been in office for so long that any capable MPs had already been promoted into high office.

There were no "new faces" who could bring fresh-thinking to the Cabinet table and reinvigorate the running of the country. And that, in many respects, is another difficulty confronting Brown.

For, while many people would like to see, among others, Alistair Darling, Ruth Kelly and Des Browne sacked, the more pertinent question is whether there are any Ministers available who could do a better job.

And the fact that the answer is a resounding "no" provides conclusive proof that Gordon Brown's reshuffle – if and when it takes place – is unlikely to save his premiership. It will be akin to rearranging the deckchairs on the Titanic as the ship sinks.

However, Brown may not be facing such a predicament if he, and his predecessors in 10 Downing Street, had spent more time concentrating on policies rather than personalities.

For, when governments have the right policies, there is no pressure on the Prime Minister of the day to reshuffle their top team