THE spectacular fall from grace of Vince Cable is almost complete.

Before May, Mr Cable would have been the choice of many as Britain’s most trusted, sure-footed and respected politician.

But what a difference an election makes.

Earlier this month, the Business Secretary found himself in such a pickle over university tuition fees that he suggested he might not vote for his own policy.

And last night, his position in the Cabinet looked precarious after the Prime Minister gave him a public dressing down over unguarded comments to undercover reporters that he was “declaring war” on Rupert Murdoch.

Humiliatingly stripped of his powers to rule on Mr Murdoch’s bid to take control of BSkyB, and informed by David Cameron that his comments were “totally unacceptable and inappropriate”, Mr Cable cut a disconsolate figure as he arrived home last night.

The problem for Mr Cameron, of course, is that he is acutely aware that he now has a ticking time bomb at the heart of his Government.

Having told the same undercover reporters that he could bring the Government down if he took the “nuclear option” and resigned, Mr Cable has exposed his deep misgivings over the pace of change.

The Prime Minister would surely like to dump his twitchy Business Secretary – but letting him loose would be an enormous gamble.