The case for fixed-term parliaments is now indubitable. The current frenzied speculation about a possible General Election is not giving our political process any credibility, at a time when it is already held in low esteem. The public don't like elections, and they most certainly dislike indecision and agonising about whether there should be one.

It is not democratic for Prime Ministers (especially unelected ones) to have the date of the election within their prerogative. Don't let anyone kid you: Prime Ministers adore being at the top of the greasy pole. ("Sunny Jim" Callaghan once said, with unusual candour, that being Prime Minister "is always the greatest thing in your life, it's absolute heaven".) Prime Ministers dread losing office. Their obsession with the timing of elections is explained by their overweening desire to retain power for as long as possible.

Of course, most politicians genuinely believe that they can do a better job than anyone else, so the issues of personal interest and national interest neatly merge in their mindsets. But the truth remains: all this speculation about whether we are to be in the throes of an election campaign next month is based not on any consideration of good governance but simply on the narrowest political imperative: power. The prize is up to five years of that precious commodity.

We should never underestimate the amount of time and energy that those who should be governing the country spend on this, to them, most overriding of all issues. Jim Callaghan himself got it spectacularly wrong when he delayed going to the country when the signs were propitious in September 1978. Instead, he soldiered on without electoral endorsement and he endured the winter of discontent (the phrase was originally Shakespeare's, amended by the then editor of the Sun, Larry Lamb) and lost to Margaret Thatcher when the election was eventually held.

Callaghan would almost certainly have won in 1978, in which case Thatcher would probably never have been Prime Minister. Gordon Brown is steeped in Labour Party history and he must be brooding, on an almost hourly basis, on Callaghan's big mistake.

And it was not as if Callaghan acted casually or whimsically. He had reflected long and hard on whether he should go to the country. His official biographer, Kenneth Morgan, noted that "like all Prime Ministers" he devoted much care and attention to the timing of the election. There was, added Morgan, a special factor in his case because he was the first Labour premier not to have been directly chosen by the electorate.

Well, at least he had been chosen in an election by his parliamentary party. As I have noted before, Gordon Brown became leader of our country by zero votes in a zero turnout. This must make him constantly conscious that he has no specific personal mandate, no electoral endorsement from the country at large. That awareness, as much as anything, might make him all the more determined to call an early election simply so that he can swim in deeper waters, a Prime Minister enjoying the clear backing of the people.

On the other hand, to call an election at a time when he has a safe parliamentary majority and the undisputed constitutional right to govern for another 32 months before going to the country would look at best opportunist and at worse downright slippery. He might just be punished by the electorate for, in effect, wasting their time. That is a sensitive matter for a leader who makes a virtue of his seriousness and his lack of frivolity.

And there is in all this another dimension: teasing the opposition. Brown is, among other things, playing with David Cameron like a grizzled old cat sporting with a very junior mouse. This may be good politics but it does not come across as statesmanlike. Most people I know couldn't care less about the tactical side of all this. They just want to know: is there to be an election or not?

Again, many of these people regard elections as a necessary nuisance, a sort of constitutional chore, while a small, worrying and possibly growing minority regard them as a downright irrelevance.

It's a relatively small proportion of the electorate (mainly the political classes and their constant attendants in the media) who find General Elections exciting and stimulating. But the people's dislike of General Elections is not healthy for democracy, for these elections do, after all, provide the best way of holding politicians to account.

Meanwhile, too many people who should be engaged in the important business of running the country - and what business is more important? - are obsessively analysing the latest opinion polls, taking soundings, reading the runes, looking for portents, even consulting the bookies. As they swither, they are wasting their time, and, more significantly, ours.

We do not pay them to do this. We pay them to provide competent and effective governance. Anyway, if a canny political fixer such as Jim Callaghan could get it so spectacularly wrong after much consultation, why don't they just accept the obvious - the timing of an election is a mystery. Great politicians such as Attlee got it wrong; lesser ones such as Wilson got it right.

All this nonsense would vanish at a stroke if we had fixed-term parliaments. Traditionalists might suggest that this would be tinkering with our revered constitution but the premier's right to call an election is a prerogative that has somewhat dodgy provenance and could be easily removed. We have had plenty of much more significant constitutional change in the past generation or so, mainly involving integration with Europe and devolution within the UK.

So if Gordon Brown is concerned with a legacy that overrides his own selfish imperatives, he must consider seriously removing one of his more significant personal powers.

There could be endless debate about how long the fixed terms should be - four years is the most obvious period, though currently a government can legitimately rule for a year longer - and when the elections should be held. (The previous seven British General Elections have all been held in April, May or June.) There would also be the inevitable worry that towards the end of a parliament politicians would move into election mode, and we might end up with longer rather than briefer periods of electioneering. But the practice of elections being called for expedient reasons would have ended, and that would benefit us all, except possibly pollsters, political advisers and certain journalists.