Ed Miliband clearly thinks that David Cameron has made a huge mistake.

That was the entire subtext of his speech to the Fabian Society conference today. Overnight reports emerged that the Prime Minister had told reporters that he wanted to “give Britain a pay rise”, clearly moving him onto Labour’s chosen “cost of living crisis” turf. And Miliband was in no mood to let the PM off without a stern talking to.

Because of course by arguing for a (much needed) pay rise for Britain, Cameron is implicitly arguing that the British people need a pay rise. And as anyone who has been listening to the Labour Party for the past couple of years will tell you, the average British workers is £1600 worse off now than they were in 2010.

Cameron, it seems, is rather making the Labour Party’s point.

Miliband was clearly pleased then, to have been presented with this opportunity by the Prime Minister. It’s turf that Labour can fight on and win, and it’s turf where Labour is not only comfortable, but where the party has been focussing much of its energy.

It seemed odd then that Cameron was even accepting the basic premise of the question on wages. He has spent much of the past four years trumpeting how much better off the British people are, only to perform a u-turn at this pivotal moment. Like the radical spending cuts unveiled by Osborne in the Autumn Statement, Miliband believes that the Tories have hubristically and fatally undermined their own arguments – Osborne on the real aim of Tory cuts, and Cameron on Tory wage failure.

So if I was summing the speech up for my mates in the pub this evening, “Dave, you’ve made a total hash of this cost of living stuff. People are skint and you’ve done nowt”.

But the aim of course was for this to be about more than than, and in the second half we got more of an exposition of what a Miliband government might look like. In the EU, cracking down on zero hours contracts, taking action on wages and jobs and – returning to a topic he’s largely overlooked in recent years – climate change and green jobs. Evidently that’s a nod towards the rising tide of Green Party support that threatens Labour’s ability to win in May, but of course thinking that votes for the Greens are all about climate change is like thinking all votes for UKIP are about Europe. It’s far more complicated than that (but that’s for another day).

It was a speech that told us what Miliband thinks Cameron is doing wrong, but it didn’t clearly outline anything new in terms of what Labour’s election campaign will be about. It was a tour of some of Miliband’s personal favourite policy spots, but it never lingered anywhere long enough to be especially memorable. It was a good speech, sure, but not one we will be talking about come election day.

But if Miliband is right, and Cameron really has made a big mistake by dragging the debate back onto the Labour territory of wages and the cost of living – then it might be the start of something after all…