Nick Clegg and his allies have often privately expressed their frustration at how Vince Cable has sought (with some success) to avoid taking full responsibility for policies such as the tuition fees rise and the austerity programme by regularly positioning himself to the left of the coalition. But what is striking today is that two former Lib Dem leaders have gone public with their criticisms of the Business Secretary. In an article for the Guardian, ahead of the opening of the party's conference in Glasgow tomorrow, Ming Campbell writes : "And by the way Dr Cable, don't be quite so gloomy!"
While recognising the importance of differentiating themselves from the Tories on the economy, the Lib Dems also want to take their share of the credit for the recovery. Cable's consciously downbeat assessment  this week was widely viewed as unhelpful.
In addition, following Lord Oakeshott's hackneyed call for the party to consider removing Clegg , Paddy Ashdown, the Lib Dem leader's political godfather, remarked : "I think Matthew’s self-appointed position as a sort of vicar on Earth for Vince does neither of them any good ... but that’s Vince’s problem".
With these interventions, Campbell and Ashdown are rather kicking a kick at a man when's he down. A year ago, when Clegg's position still seemed at risk, Cable was viewed as the party's leader-in-waiting. He memorably signalled his interest  in the position ("I don’t exclude it – who knows what might happen in the future...The worship of youth has diminished – perhaps generally – in recent years.") and was aided by a poll showing that the Lib Dems would gain  four points with him as leader. But the Eastleigh by-election (which proved that the party could win in its strongholds) and the return of growth (which deflated Cable's call in the New Statesman for a plan B ) mean that his star has waned. As I suggest  in this week's NS, Tim Farron is now the man to watch.