Hmmm. Well I hate to suggest that I may have written in haste, but on re-reading the exchange at PMQ's just before the Speaker interrupted David Cameron, I am bound to admit that Cameron does not appear to have mentioned the Labour Party in his question, thus rendering the Speaker Martin's rebuke somewhat redundant. I suspect Martin was seeking to correct Cameron for what he thought he was going to say, rather than what he actually did say, which is a rather careless, and hasty, mistake for someone as august as the Speaker to make. There are numerous suggestions going round that Martin was abandoning his neutrality to act as a Labour partisan, but I don't think this fits the bill at all. Anyway, you can make up your own minds by looking at the exchange yourselves - or reading it. And my main point still stands - Cameron needs to buck up his ideas about how he uses PMQ's and what it says about him to the country.