In those papers still sympathetic to Gordon Brown, a common theme recently has been the appalling disloyalty being shown to him by his MPs - all of whom seem to be briefing against the PM, anonymously of course. Take this leading article
in the Independent
The PM and the curse of his disloyal courtiers
Labour MPs fanning the flames of regicide should be ashamed
Well, really this is a case of what goes around, comes around. Gordon Brown and a coterie of supporters spent the bulk of the last ten years briefing against Tony Blair, blocking reforms, agitating for Blair to hand over power and other acts of flagrant disloyalty. The example given was that there was no need to be loyal to the leader if that loyalty conflicted with your own personal ambition. It's hardly a surprise therefore that Brown cannot rely upon the loyalty of his party - he has done more than anyone else to destroy the value of loyalty in the Labour Party.
By the same yardstick, it was impossible for Iain Duncan Smith to call for party unity and discipline when he had first made his name as one of the more intractable rebels over Maastricht. He simply did not have the authority to call for discipline given his own background of disloyalty.