Could the moment have arrived for Ken Clarke to split the Tory Party?

A handful of Liberal Democrats has begun to think about a new alliance after a shift of tectonic plates in the Tory Party

If Conan Doyle were around to turn the political assassination of Iain Duncan Smith into a Sherlock Holmes story, would it not contain the following exchange between Inspector Gregory and the Great Detective? "Is there anything else to which you would wish to draw my attention?" "To the curious incident of the Tory left-wing plot to unseat the party leader." "But there is no Tory left-wing plot to unseat the party leader." "That was the curious incident."

Curious indeed. For here is a beleaguered Tory leader who happens to be the most right wing and Eurosceptic in living memory, and the least rebellious faction is precisely the one most ideologically opposed to what he stands for - including many of those who campaigned for Ken Clarke in 2001. Stephen Dorrell, one of the more prominent former cabinet ministers on the left, has actually gone out of his way to defend Iain Duncan Smith in interviews. It's not only that Clarke himself stands way above the fray, refusing to indulge in anything as petty as a plot; it's also that those most involved in his last leadership campaign have, by and large, refused entreaties to join the soi-disant plotters.

On Wednesday morning of last week a group broadly on the left of the party convened for a convivial breakfast at the flat of Mr Clarke's old cabinet colleague John Gummer. Accounts of this supposedly secret meeting vary, as, it is safe to assume, did the opinions of those who took part in it. There was quite a lot of talk among the group - which did not include Mr Clarke himself - of the severe difficulties Mr Clarke would face in once again securing the endorsement of the party membership in a run-off, however well he did among MPs. What is clear is that no plan for eliminating Mr Duncan Smith, much less one for replacing him, emerged from the breakfast.

So why have the left been so quiet during the ferment when they have reasons of principle as well as electoralism to see him ousted? A ferment which reached a new climax after Mr Duncan Smith's weak Commons performance yesterday. And after the businessman Sir Stuart Wheeler gave the plotters a powerful new casus belli by making clear he was not going to waste any more money on a Tory party led by Mr Duncan Smith. And after the bleak analysis ominously delivered to the party leader by his chief whip, David Maclean.

The answer isn't wholly simple. The left - as they are called now but wouldn't remotely have been in the days when their natural forebears Macmillan and Heath actually led the party - still retain traces of the stoical old yeoman Tory squirearchy for whom intrigue is just a little distasteful. Much more importantly, however, several of its more intelligent adherents tend to think that the party's fortunes will not be dramatically transformed by the replacement of Mr Duncan Smith by someone of the same views.

Finally there is the problem that the new leadership rules, requiring a ballot of the members after one of the MPs, make it almost impossible for any of the plotters to be sure of the outcome of their plot - unless all the candidates are prepared to agree in advance that only one will go forward to the ballot of the party membership. And for the left that might - crucially - involve a pact between Mr Clarke and Michael Howard which would, because of their differences on Europe, be extremely difficult to obtain. In all other circumstances regime change is the easy part, planning the post-war reconstruction almost impossible.

But the paralysis consequent on all this raises the curious incident of another dog that hasn't barked in the six-year-long Tory crisis. A similar crisis in the Labour Party had spawned a breakaway by the SDP within two years of Labour's defeat in 1979, and an electorally powerful, if not ultimately triumphant alliance with the Liberals. A handful of more power-hungry Liberal Democrats has now begun to think in deepest privacy about how much more triumphant an alliance could be after a similar shift of the tectonic plates within the Tory party.

Their argument goes something like this. Suppose Ken Clarke led the formation not of a new party, but of a separate grouping of independent, pro-European, economically mainstream Conservatives in the House of Commons. They would have to resign the Conservative whip, of course. But the mechanism would be less like the SDP than the independent Asquithian Liberals who fought the 1918 "coupon election" against the Lloyd George coalition. Except that in this case Charles Kennedy would make an electoral pact with the Clarkeite independent Tories.

And in these circumstances Mr Clarke, reinforced by his stand against the war in Iraq, by the funding of pro-European business, and by his formidable experience in two great offices of state, would be promoted as the alternative Prime Minister. Such an alliance might promise the euro referendum Tony Blair looks increasingly unlikely to deliver. It would combine the appeal of one of the biggest figures in British politics with the formidable electoral skills of the Lib Dems. And above all it would threaten the Government of Tony Blair in a way that it hasn't been threatened since 1997. It might even just win.

The obstacles to this heady scenario are great and numerous. Leaving aside the objections of the less power-hungry rank and file of the Liberal Democrats, they start with the personal and political character of Mr Clarke himself. You can almost hear him scoffing at the idea.

On Europe, it could help to fulfil many of his most cherished goals. But this is a man who sees himself with good reason as the true epicentre of the party and the clique which has ruled it - and might continue to do so if and when Mr Duncan Smith is replaced - as interlopers foreign to the broad mainstream traditions of the Conservative Party. A politician who has frequently proclaimed his own constancy as his greatest political virtue is hardly going to find it easy to transmogrify into the Roy Jenkins of the Conservative Party. He would find it more difficult than most to take the Lib Dems seriously - for all the modest shift towards his own way of thinking reflected in the promotion of economic "dries" in Mr Kennedy's recent reshuffle. And he can hardly even now - after topping the poll among MPs in 2001- be ruled out as its leader if the other candidates could agree among themselves that he provides, as he surely does, their best chance of success.

So it's a cloud no bigger than a man's hand, hovering wispily in the heads of a few Liberal Democrats. But it matters for two reasons. One is that in at least the medium term, it's hard to imagine that Conservatives most eager for office will put up indefinitely with a Tory party which, under whatever leader, continues to repel much of mainstream electoral opinion. And second, the very fact that such a scenario, however improbable, cannot fail to quicken the pulse underlines how much Mr Clarke remains, for all his current reticence, one of the potential pivots of British politics.

d.macintyre@independent.co.uk