Of course, the issue of the Union has been gaining speed over the past few months. But Alexander's words have brought it to Brown's gate far quicker than he'd have wanted. The media (and the Scottish public?) will now be eager for a response from the Prime Minister. With his political capital being so low, the problem is that anything he does could be damaging. If he ignores Alexander's pledge, then he's a ditherer. If he stamps down on it, then he's scared, and unwilling to give the Scottish people a say. And if he allows her to proceed, then he could be setting Labour up for an epochal defeat.
Either way, it's yet another example of Brown's waning power over his own party, and more encouragement for those who would be king.