The thing is, when you think about it for a second, hidden within the language of that argument there remains the same original battle line. After all if Labour are going to have nice cuts, ergo cut less, then they can still make the claim that they're spending more. Tory cuts versus Labour investment remains intact, it's only the words that have changed.
In a strange way though, the change in language is almost like a repeat of the Tories 2005 election argument. Back then they tried, and failed, to argue that they would increase spending only do it slower than Labour. We now appear to have Labour trying to argue that they will cut spending only do it slower.
It's quite a nuanced argument which makes it a risky strategy. Especially when you couple it with the inevitable arguments that will be leveled against Labour - that they recklessly spent in the good times, so why should anyone trust them not to continue to be reckless in the bad times? There is also another positive side for the Tories in this change of language.
If Labour are now going to talk about cuts, it effectively neutralises one of the standard play book attack line that its specialised in for the last 15 years, the formula of which looks like this.
Ul = c \ ucThat is, an argument will be deployed that talks of an arbitrary unit loss (Ul), which is calculated by taking the value of a proposed cut (c) and dividing it by the unit cost (uc) of the given arbitrary thing. For example, if the unit cost of one teacher is £1, and a cut of £1000 in back office functionality in the Department for Children, Schools and Families is proposed, then it will be argued that the cut means a loss of 1000 teachers.
Whilst it is not beyond the realm of possibility that Labour would continue to use this formula to extrapolate a nastier endgame for a Tory cut than their own, it seems unlikely. After all, are they really going to want to have an argument where they say "ahh yes, but we're only going to lay off 9,000 policeman unlike those bastards over there who are going to lay off 10,000"?
By switching tack and trying to make the dividing line one of nuance, between who can cut less but still cut, what they've actually done is show that they're losing the argument and having to follow the lead of others. That I would imagine is the line that Tories will take to Labour now.
It's not going to be "cuts vs. cuts" as some say, but rather "leadership of ideas vs. subordination to those ideas". Where Tony Blair famously in Opposition said to Major, "I lead my party. He follows his", in 2010 the battle line switch by Labour means Cameron can say, "I lead my party. He follows mine".