What should Gordon say at PMQs?

Gordon Brown must be sick to his stomach about going to have to face David Cameron at PMQs today. The Tory leader, who thrashes him every week, is bound to make the case that this government is just serially incompetent and a busted flush. So the question is: can Gordon say anything to counter this? Would a very un-Gordon like, full apology do the trick? Or, would it just make him look even weaker?