In a largely failed attempt to prevent the media referring to the "bedroom tax", the Conservatives took to speaking of the "spare room subsidy". But the confusion this created is that the bedroom tax isn't the spare room subsidy; it's the abolition of the spare room subsidy. Regardless of this, many now use the terms interchangeably, including, it seems, the Tories themselves.
In a press release issued this lunchtime on welfare, the party stated that the "spare room subsidy" is "opposed by Labour". Were that the case, of course, there would be nothing to argue about. If, in their determination not to refer to the "bedroom tax", the Tories end up fluffing their attack lines, perhaps it's time they concededed defeat.