Things have come to a pretty pass when the Labour Party is launching a campaign with a deficit clock to expose George Osborne’s shortcomings. But they are about to do today, I understand, highlighting how much extra the government is borrowing over the four days of the Tory conference compared to last year: £277 million, they say. I’ll post the link when it becomes live.

Significantly, Labour is shifting from being in a position of deficit denial towards a position where they will (I suspect) sign up to Osborne’s spending plans. As Balls has found out, Osborne’s game is to dress up only-slightly-modified Labour spending plans with Tory language. But Osborne, and David Cameron, have overdone it with the rhetoric. Just 10 per cent of voters realise that the debt is rising. Before, the voters would not be any the wiser: Labour refused to point this out, having more fun lambasting the Tories for cuts. Now, Labour is changing its tune.

But in my opinion, Labour has chosen weak ground by going for deficit, rather than debt. It is exploiting a relatively freakish fiscal event: that the deficit (ie, the amount by which debt is rising) is going up. It’s true – and deeply embarrassing for Osborne – that the deficit was £59bn in April-August 2012, compared to £48.6bn for the same period last year. But there is no doubt that the deficit is going down overall. It’s true that £10.6bn over those five months works out at £802 a second. But that the PSNB was higher in April-August does not, by any means imply, that it’s higher right now. And it certainly would not be by the same amount per second.

Also, Labour is using Westminster wonk words. Its use of ‘borrowing’ is not what the ordinary voter would understand: ie, a bank overdraft or a credit card statement. It is Treasury shorthand for Treasury jargon: ‘Public Sector Net Borrowing’ which is another word for ‘deficit’. All this will just serve to confuse people further.

If Labour had run a simple debt clock, they’d be on stronger ground. The coalition is increasing debt more over five years than Labour did over 13 years. This is a far simpler and more powerful point. As things stand, Labour has chosen a rather short-lived attack: as soon as the deficit starts to fall, which it will, it will have to shut up.

Nonetheless, it’s an interesting political development that Miliband has taken the fight to the Tories over public finances. Osborne can thank his lucky stars that Miliband has not, yet, learned how to choose the best weapon.

Tags: Borrowing, Conservatives, Debt, Deficit, Economy, Labour, Public finances