By Nick Assinder BBC News Online political correspondent

Anyone looking for signs of secretive plots to oust Iain Duncan Smith during his latest crisis have been coming up empty handed.

Despite all the dissatisfaction with his leadership and all the mutterings about him - and former leader Margaret Thatcher has been as helpful as ever - no one is out there organising. So far.

No active plotting against Smith

There is any amount of chatter about who could be a potential runner - with all the usual suspects topping the league.

But there is still no evidence that supporters are doing the necessary groundwork for a challenge.

That is not to say it will not happen. The Tories could still panic themselves into it. But at the moment it isn't there.

Dream ticket

So that has left a vacuum which the Westminster gossips are filling with increasingly imaginative scenarios.

Probably the most enjoyable at the moment is the suggestion of a "dream ticket" of Kenneth Clarke and Michael Portillo.

Presumably, the logic is that they are so obviously the leaders the party should have, that a grateful membership would leap at the chance of putting one of them into the top job.

Portillo doesn't want job

It is precisely the same cunning plan that was being put about at the early stages of the original leadership election.

Mr Portillo was seen as rightish - at least where it mattered, over Europe - hugely talented and charismatic.

Liberal, Euro-enthusiast Mr Clarke was seen as the weightiest of the so-called big beasts, with an almost natural leadership style.

Put the two together and you unite the warring wings of the party behind an unstoppable partnership.

Liberal agenda

No one bothered to ask them , of course, and it soon became clear that, for whatever reason, neither was ready to abandon the chance of the top job just to play second fiddle.

And, in any case, Mr Portillo turned out not to be the product as originally advertised. He had been converted to the liberal agenda somewhere along the way, confusing many of his former allies on the right.

There is one big difference this time. Mr Portillo has now publicly denied any desire ever to become leader on so many occasions that a change of heart would blow his credibility out of the water.

Clarke still wants to lead

So we must assume he means it. But does that mean he would be willing to back the man who has never abandoned his ambitions to be a Tory prime minister?

Mr Clarke is still seen as the only natural election winner by many Tories, including himself.

He may well be one of yesterday's men and well over the hill, but he still wants the party to beg him to do his duty and rescue them.

So for some the logic is obvious. A Portillo backed challenge by Clarke would be unstoppable.

It's worth remembering at this point, however, that they were both rejected - flatly in Mr Portillo's case - last time around.

And there are precious few signs the party members, who get to vote on this, are ready to admit their glaring error of judgement.

It would be foolhardy to rule anything out at this stage - the Tories are in such a state that almost anything is conceivable - but the dream ticket talk looks much more like wishful thinking in some quarters.