Michael Brown: Clarke is an appealing candidate, but is he tainted by his role in 18 years of Tory rule?

A party under Ken's command will hand Gordon Brown the easiest weapon in the Labour armoury

In the immediate aftermath of the general election defeat, Michael Howard announced that, already aged 64, he would be too old to lead the Tories into another election in 2009 or 2010 - when he would be approaching 70. The implication was that Ken should also be ruled out. But so far as age is concerned, I see no reason why this should automatically debar Ken. I have often remarked how, in spite of his healthy appetite, his love of the occasional pint and his prodigious consumption of cigars, he seems to have more puff about him than Tony Blair.

He never seems to get ill and, while there is a political downside to his frequent international trips abroad to developing countries on behalf of British American Tobacco, such visits nevertheless prove that he has the stamina for the demands placed on any modern prime minister faced with the consequences of jet-lag. Confronted with the prospect of a choice between someone who is too young and someone who is too old, there is much to be said for opting for age before beauty.

Not that I am suggesting that Ken's physical appearance is unattractive. Shambolic though he sometimes appears in his trademark suede shoes and invariably crumpled, old fashioned, double-breasted suits that fail to button up across his considerable girth, this unique style is a welcome antidote to the carefully constructed clones manufactured by spin doctors and image-makers. It is a style that accounts for Ken's consistent ability to shine through as the Tory with the greatest recognition factor.

And most voters can certainly imagine Ken fitting the mould of Prime Minister. Grandfather (as of a fortnight ago) he may be, but as a Prime Minister he would present more of an avuncular figure in the style of the late Jim Callaghan. From the day Margaret Thatcher took office in 1979 until the day of John Major's defeat in 1997, Ken - along with Sir Malcolm Rifkind - served continuously as a minister. His cabinet experience - Health, Education, Home Affairs and Treasury - is unrivalled by anyone else in Parliament, either on the Labour or the Tory benches.

In short, in terms of curriculum vitae, Ken has everything going for him. Everyone agrees that he is, like Charles Kennedy, a fully paid-up member of the human race. His chances of winning are as good as anyone else's and no rival, especially David Cameron or David Davis, should underestimate his appeal. Already Mr Clarke has managed to attract support from both Ann Widdecombe and John Bercow, whose views on social issues and "modernisation" are usually diametrically opposed.

But there is as much downside for the Conservatives to Ken's candidacy as there is benefit. First, there is the little matter of his relationship with the rest of the party. Of course, if he wins the series of exhaustive, eliminatory ballots - should they be confined to MPs - he will probably manage to unite the parliamentary party as well as anyone. No doubt all rival candidates will serve in his shadow cabinet and, notwithstanding some bruised egos, the desire for unity will initially prevail.

But there will be divisions among the wider party membership which, if the decision is restricted solely to MPs, will feel cheated that Ken has been imposed on it by a parliamentary coup d'état. It never ceases to amaze me that Ken predicates his whole appeal on his ability to "reach out" to the wider electorate while failing to overcome the opposition of the party membership. They appear, from anecdotal evidence, to be the most resistant to his new stance against the euro and are not wholly convinced by his U-turn.

Indeed, the party membership may yet be the Achilles heel for Ken's campaign. Yesterday, several influential party bigwigs, in a letter to a national newspaper, called on members of the National Convention, currently receiving ballot papers, to vote to retain the present system whereby the 300,000 membership has the final say over the top two candidates in the parliamentary ballot. Rumour has it that Mr Clarke might not pursue his bid unless he is satisfied that the choice will be solely in the hands of MPs - although this was dispelled by his close supporter, Ann Widdecombe.

That stance would be guaranteed to get the goat of the constituency chairmen, who are the largest group comprising the Convention. Its deliberations will conclude on 27 September, and the possibility that the necessary two-thirds majority not being achieved has increased by what some say is Mr Clarke's arrogance in wanting to bypass the membership. Indeed, constituency chairmen who support any other candidate - especially Mr Cameron or Mr Davis - now have every incentive to block the rule change. The debate about the rule change is now entirely bound up with the activists' attitudes towards Mr Clarke.

Ken's greatest strength, his ability to best and beat both Tony Blair and Gordon Brown at the dispatch box, is also potentially his greatest liability. By the time of the next election, it is likely that Mr Brown will be the incumbent Prime Minister.

Ken stated yesterday that he relished such a confrontation "on home ground". The two sparred for four years when Ken was Chancellor and Brown was his shadow. This was the pitch made by Michael Howard when he became Tory leader in November 2003. Much was made of the fact that, during the late 1980s and 1990s, Howard was shadowed at Employment and the Home Office by Blair. But during the recent election, Labour successfully pinned on Mr Howard guilt by association with the unpopularity of the Major years.

Mr Brown made much, during the 1997 campaign of the Tory economic record. Although it is true that Ken secured a "golden" economic legacy by his stewardship of the economy after he succeeded Norman Lamont, following the ERM debacle, for better or worse, the public perception was of Tory economic failure. Ken was unable to escape the opprobrium of being associated with the unpopular - albeit necessary - economic decisions taken by the Tories.

Even in 2009, a Tory party under Ken's command will still hand Mr Brown the easiest weapon in the Labour armoury: remember the 18 Tory years? Ken was at the heart of it all.

mrbrown@talktalk.net