Vince Cable, who is in China at the moment, has released the following statement naming Lord Oakeshott as the source of the leaked ICM polling (pdf):
Lord Oakeshott’s actions are totally inexcusable and unacceptable. I have made it very clear repeatedly that he does not speak or act for me.
Commissioning and publishing polls without the consent of the Member of Parliament, as in the case of Sheffield Hallam, is utterly reprehensible.
There are undoubtedly raw feelings in the wake of poor local and European election results. We need to respond in a measured way. Public speculation about the leadership is an unwelcome distraction and as I made absolutely clear yesterday there is no leadership issue as far as I’m concerned.
The internal poll looked at how the Lib Dems would fare in 2015 in four seats they currently hold: Redcar, Cambridge, Wells in Somerset, and Nick Clegg's Sheffield Hallam constituency. The Guardian, which first reported the leaked data, said that the party faced “electoral oblivion”, but would perform marginally better under Cable's leadership.