Is Osborne right to warn about sterling now?

So, George Osborne’s unveiled his new line of attack on the Government – warning that, in light of sterling’s recent plunge, Brown’s addiction to debt could trigger a run on the pound. It’s a prognosis not entirely without basis, but is now the right time to make it, politically? After all, the trends aren’t currently heading in the direction of the Shadow Chancellor’s worst-case scenario, and the devaluation of sterling could even result in a few benefits. Gary Duncan puts it best in today’s Times:

“How much does any of this really matter? There are two main dangers. First, as Mr Osborne argues, a weak pound that makes it even less attractive to invest in Britain could make it harder for the Treasury to borrow in the markets by selling government bonds. In turn, that means that it may end up having to pay more to finance surging government borrowing.