Charles could save the monarchy, but only if his mother abdicates

NATURALLY, NONE of the usual suspects talked about the Prince of Wales's private life to the latest turbulent biographer. Like the cast of an Agatha Christie novel, they all have alibis. M Poirot would spot instantly that a lot of them share the same one.

Any number of royal friends have restricted comments to the Prince's charitable endeavours, breathing no word of any trouble he may have had with the late Princess. Could briefings have come from more official sources? Stephen Lamport, his private secretary, says he talked to the author, Penny Junor, only about the Prince's dedication to architecture and organic farming. His deputy, Mark Bolland, issues the sweepingly vague denial: "I do not go around making personal comments about anything."

And yet somehow, a vulgar form of princely redress has emerged for the secular canonisation of Diana. Never mind the Prince's adultery; we are appraised that "she done it first". This is supposed to clinch the argument - and I suppose it does among those sections of society whose code of morality is derived undiluted from Anna Karenina's St Petersburg, or the duelling codes of 19th-century Prussia.

Ms Junor's book is entitled Charles: Victim or Villain?, which is as idiotic and cruel as entitling a book about a famous woman "Madonna or Whore?" The heir to the throne is reduced to a category, trapped in a kind of post-Diana cage. It is possible that his desperation to escape this torment seduced him into believing it was in his interest to balance the record of his marriage. Or perhaps others decided it for him.

If only people understood how bad it was for the Prince, they would not be so slavishly devoted to Diana. Such is the reductive logic of those supporters who have been encouraged to spin like demented tops about the ghastliness of Diana and the underestimated qualities of Camilla Parker Bowles. At least two newspapers have been helped with extensive background for series intended to put the Prince and Camilla in a better light on the eve of Charles's 50th birthday.

The Prince now has a dangerously hyperactive alternative court around him. Its news management is modelled on New Labour's belief that a single message can be pumped out through various channels in the media until it becomes unquestioned. Those who seek to advance his interests in this way neglect one important difference. Tony Blair knew exactly what he was pursuing with this strategy - a parliamentary majority. He also knew the means to achieving this: getting more people to vote Labour.

Prince Charles's difficulty is that he cannot openly state what his desired goal is - namely to succeed to the throne as soon as possible, even if that should entail his mother forfeiting the crown before her death.

He has spent his life preparing for the office of monarch. But as with Tantalus hankering after the grapes, the prize grows more distant the more desperate he becomes for it. He sees in monarchy an institution that needs updating, yet he knows that this cannot happen with the Queen and the even less flexible Prince Philip at its head. The recent attempts to make the Queen seem more accessible by inserting the poor woman into pubs, taxi cabs, the Tube - on a kind of rolling tour of Ordinary Britain with compulsory football references - has served only to underline her isolation.

Charles may be something of a dilettante whose talents are, at times, spread too thinly. But his Prince's Trust successfully anticipated the Government's New Deal by several years. We don't have to share his views on architecture, global warming or the opaque spiritualism of Laurens van der Post to discern someone concerned about the fate of mankind and its surroundings, and recognise in his anxiety a slice of our uncertain times.

On the eve of his 50th birthday, he is at the age when most men are planning their early retirements, not their first day in the job they were born and brought up to do. Unless he becomes king soon, his life will be remain wedded to a past dominated by his failed marriage and its bitter consequences.

The family that calls itself The Firm is ripe for a takeover by the next generation. In the interests of both her eldest son and the stability of the institution she pledged during her coronation to uphold, the Queen should plan her retirement. She is over 70 years old and has ruled for four-and-a-half decades. Royals, like the rest of us, enjoy greater longevity than ever before. If the Queen lives as long as her mother, Charles will be past his three score years and 10 before the throne is his, by which time Prince William will be having the same agonies about a life spent waiting. The arithmetic of mortality runs against waiting for the death of the monarch to crown the heir.

While we're in a radical frame of mind, why not bin the lot of them and consign the monarchy to the same outer darkness as the hereditary peers? The republican question hangs heavy over the whole debate, but there are two reasons why it should not triumph in the foreseeable future. The first is that the public would be unlikely to vote for the abolition of the monarchy in a referendum. Only constitutional reform fundamentalists really believe that inadequacies in the British state result from the symbolic presence of a royal family.

The second is that an enlightened and mature democracy can afford to judge institutions on their merits, and retain or dispense with them accordingly. The United Kingdom is undergoing devolution, whose consequence will be a fundamental realignment of its constituent parts. Hitherto, there has been a blind belief that this will not affect England, which will carry on much as before. It won't.

We are not yet fully aware of the impact devolution will have on all of us, and of how rapidly a Scottish parliament is likely to seek further powers from Westminster. An increasing number of the Tory Party's yeomanry is seeking an English parliament in order to regain a majority in at least one assembly in the kingdom. Scottish Nationalists have pledged to hold a referendum on the future of the monarchy within a year, if they gain control of the parliament in Edinburgh.

With such uncertainty about our shared identity, a single, non-political head of state embodying the unity of the UK and the growing diversity of its governance is an asset not to be wasted. This will entail a royal family that spends more time in Scotland - and not merely closeted amid the tartan kitsch of Balmoral. By the same token, it must become a stronger presence in the life of Wales and the devolved Ulster.

The most dignified solution would be for the crown to pass to Charles in the year 2002, the 50th anniversary of the Coronation. It would be an abdication in name only, and easier on all concerned not to call it that. This is no national trauma, as Edward VIII's abdication was, but a vote of confidence in the monarchy's ability to adapt. Its job description has changed because Britain has changed.

The alternative is a creeping death which no amount of spin-doctoring, or advice from well-intentioned friends, can cure.