By Nick Assinder BBC News Online political correspondent

Iain Duncan Smith showed some courage

But after this week's question time I've a pretty fair idea of what the atmosphere might be like.

There was an air of guilty excitement and anticipation hanging over the whole affair.

Even before the principal players were in their seats, the MPs were patently hyped up. The adrenalin levels were through the roof.

Whatever the outcome of the looming Tory leadership vote was going to be, they knew there was going to be a great deal of pain before this particular day was out.

And, of course, for many there is no better spectacle than someone else's suffering.

No scruples

Mr Duncan Smith didn't look like he was suffering much.

Indeed, he seemed perfectly at ease with all the shouts of "goodbye" and the theatrical stabbing movements from the Labour benches.

Clearly, even though there was only one issue in the minds of every single MP in the packed chamber, no one was going to actually mention it, were they?

Step forward the beast of Bolsover. Dennis Skinner - on the sort of off-the-cuff form only he can manage in the Chamber - has no such scruples.

Would the prime minister consider making back stabbing a criminal offence, he asked.

Blood lust

Now Mr Skinner has never been one to use blunt cutlery when attacking his own leader.

So the prime minister was probably delighted that his blade was pointing at the opposition frontbench on this occasion.

The prime minister, encouraged by his blood lust MPs, couldn't resist it.

"I want to admit, in the past few years that crime has gone up," he answered, with absolutely no sense of irony.

Sitting behind him were any number of MPs who have spent the past few months sharpening their own knives and with their eyes firmly focused on his rear.

And he was dealt a couple of flesh wounds by his own side over the issues of top up fees and cancer care lottery.

Still, this was once again all about Iain Duncan Smith.

The Tory leader turned in a perfectly serviceable performance. Under the circumstances, it might be seen as courageous.

And that is a quality he has needed in bucket loads recently.