By Nyta Mann BBC News Online political correspondent

So here we are again.

Barely a year into Iain Duncan Smith's leadership and serious talk of getting rid of him is rife on the Conservative benches.

Will the quiet man fall victim to a not-so-quiet plot?

Tories at Westminster know that raising the prospect of a leadership challenge so soon after the last contest runs the risk of making the party look pathologically ungovernable and completely unelectable.

William Hague: A good Commons performer

After all, if they can't be trusted to get the choice of their own leader right, how on earth do they expect voters to trust them to run the country?

But so low is morale, and so utterly bleak the opinion polls, some are now convinced there is no alternative.

They point to lacklustre performances at the Commons despatch box - a stage on which William Hague shone, regularly besting Tony Blair at prime minister's questions.

'We must do something about Iain'

Mr Duncan Smith's natural allies on the Tories' hard Eurosceptic right, who helped him win last year's leadership race, accuse him of having been captured by the modernisers' agenda.

The modernisers accuse him of being way too slow in dragging the party into the present era of politics.

And though choosing a new leader is a much more cumbersome business than it used to be, involving a mass ballot of party members rather than men in grey flannel suits, MPs report that grassroots Tories in their Conservative associations have lost the automatic leadership-loyalty they used to have.

Baroness Thatcher: Won three elections, dumped by the Tories

"This is more than us Tories simply reverting to type and plotting against the leader like so many times before," explains one frontbencher.

"The completely new thing amid this latest talk of revolt is that it's our local association members who are in complete despair and telling us, their MPs, we must do something about Iain."

Another sign that should alarm Mr Duncan Smith is that the Tory whips' office, traditionally the unbreakable ring of steel in terms of support for the leader in times of crisis, appears not to be playing that role at the moment.

Who wants the job?

Tory MPs point to next month's Queen's speech: how he performs in his response to it may prove to be a decisive "tipping point" as to whether he can stave off the speculation about his position.

If he doesn't manage to see it off, the resulting instability may mean that anything could happen - and as Conservative history shows us, the party is far more brutal and unsentimental about dumping its leaders than Labour.

Lest we forget, the party had no compunction in getting rid of Margaret Thatcher, a three-time election winner, once it decided she would lose them the next one.

But before anyone gets too carried away, it is also worth remembering that there don't as yet appear to be clear answers to two vital, linked questions: first, who would want the Tory leadership at this present moment given the state the party is in right now? Second, who do the Tories actually really want?

The absence or otherwise of those answers is likely to play as much a part in the fate of Mr Duncan Smith as the undoubted discontent currently being expressed.