Exhibit A: the Labour chief whip, and key ally of the PM, Nick Brown, has just said that Martin is "one of us" and that "the establishment" forced him out. Rather than subtly claiming credit for the Speaker's departure, it seems that Downing Street is passing the buck. And onto the "establishment," whoever they might be.
Throw in Exhibits B and C, and we get a clearer picture. The PM is making frequent references to Parliament being like a "gentleman's club," and he dropped a jibe about Douglas Hogg's moat in PMQs earlier. So despite Brown's claim to be rising above party politics, it really does look like he's overlaying his favourite "Tory toff" attack on the expenses scandal. And rather than making Michael Martin a scapegoat, the implication is that those nasty "Tory grandees" have whacked the Speaker because they want to maintain Parliament as their own private little Bullingdon Club. Tsk, tsk, and all that.
Maybe I'm overstating all this, but I still think it's important to flag up. After all, Brown is - in the loosest sense - right when he says all of Parliament needs to come together and take drastic action to sort out this mess. It would be a pity and a disgrace if he's not prepared to do that himself. For, in the end, voters deserve better than venomous spin and bluster.
UPDATE: The Standard's Paul Waugh has more on this over at his blog.