Lord Ryder of Wensum said the Prime Minister "lacks coherence" and needed to take charge before he loses his grip on power within the party.
Daily policy announcements and "pointless gimmicks" should be left to junior ministers, while Mr Cameron sets out the "big picture", he said, telling the BBC the Prime Minister needed to ditch the party's co-chairmen Baroness Warsi and Lord Feldman.
They should be replaced with an MP, who could act as a "lightening conductor" and "firefight" internal rows within the party.
The Labour leader had a sense of humour after being hit on the shoulder with an egg during his interview with ITV Meridian.
Labour was only kicked out of office a couple of years ago and yet here it is giving the government a political wake-up call.
The Nationalist party led by First Minister Alex Salmond are expected to snatch Glasgow City Council from Labour hands.