From tripping the light fantastic to toppling into an elephant trap

Vince Cable was the politician the public trusted to talk sense. Now, he has hoofed himself into a hole. Matt Chorley surveys the damage

(GUY LEVY/BBC/PA Wire)

For an hour last night, Vince Cable could safely turn the TV on to watch himself without worrying about being the subject of another story about his indiscretions. The demoted Secretary of State for Business could delight in his pre-recorded American smooth and foxtrot on the Strictly Come Dancing dancefloor, showcasing fancy footwork that has been all too lacking politically. To his detractors, his appearance on an entertainment show was further proof of the vanity of a politician who has begun to believe his own hype.

His reputation has been dragged through the Westminster gutter with all the elegance of a horizontal Ann Widdecombe. Boasting to two undercover Daily Telegraph journalists at his constituency surgery about his importance and his "constant battle" with the Tories was embarrassing enough. When the BBC obtained a fuller transcript which revealed Mr Cable's declaration of "war" against Rupert Murdoch's media empire, it triggered a crisis in the coalition and raised doubts about the minister's judgement which will last much longer than any other of the so-called revelations in the sting.

But the 67-year-old's status was waning even before the tape recorder started rolling. In February, a poll of party members by LibDemVoice gave him a net satisfaction rating of 95 per cent. When the exercise was repeated last month, his rating had slumped to 47 per cent.

At a meeting of Lib Dem ministers earlier this month, Mr Clegg signalled the decline of his Business Secretary: "Even when Vince was at the height of his powers and could do no wrong, it didn't translate into support for the party." Others in the room felt the poll was a painful public confirmation of Mr Cable's downfall, not least over the handling of university tuition fees.

The Murdoch story broke as a Cameron-Clegg joint press conference finished on Tuesday lunchtime. Mr Cable, whose quasi-judicial role in adjudicating on News Corp's bid to buy BSkyB outright now seemed untenable, slipped quietly into Downing Street and was told he was to stay, but stripped of his media powers. "We actually don't want to lose him," said one Clegg ally.

Others, however, talk of him losing "clout", his authority "diminished". Labour's Tom Watson put it more bluntly. "Six months into the Conservative-led government, he's left himself looking like, and let's not mince words, he looks like a cock."

Mr Cable is the week's big loser. Stripped of media powers, slapped down by the PM, embarrassed across the front pages: his calls for tougher action on the banks and opposition to the immigration cap will now carry less weight. His wife, Rachel, was left to answer reporters' questions on the doorstep, while her husband was "working from home".

Yet the Lib Dems – for whom over-optimism was an electoral strategy – can see a silver lining in even this cloud. Mr Clegg's aides take heart from the impression that their ministers are not all "Tory blue" and are uneasy with coalition policies. "There are probably a lot of Lib Dem members who are quite pleased," said a senior source. One former party leader, Lord Steel, suggested activists would be "cheered" by ministers "fighting their corner". A bounce in the polls is predicted.

Remarks by other senior Lib Dem MPs, including Michael Moore (Tory ministers are "on a different planet"), Jeremy Browne (Conservative EU allies are "nutty") and Norman Baker ("I don't like George Osborne"), chime with party activists. They are not far from their public statements, if in more colourful language. Andrew George, a left-wing Lib Dem backbencher, made clear his preference for staying in the coalition "to engage in these battles rather than be a debating society on the opposition benches".

That is very much Mr Cameron's attitude, as he once again emerges from a crisis without getting his hands dirty. His coalition partners have inadvertently reasserted their independence, he has acted swiftly, and potentially cleared the way for his old pal Rupert Murdoch.

MPs are already making jokes about it. Tim Farron, the new Lib Dem president, wrote on Twitter: "My Dad just rang and offered to come to my surgeries and frisk the ladies just in case. I told him he should be ashamed of himself."

Mr Clegg has made plain his irritation at the revelations. Mr Cable remains a lame duck. Many suspect if the timing had been different and the interminable inquiry into David Laws's expenses had concluded, the short-lived Chief Secretary to the Treasury could have made a swift return to the Cabinet last week.

Instead, the final decision on BSkyB will now be made by a Conservative – Jeremy Hunt, the Secretary of State for Culture, Media and Sport – who is considered far more likely to give it the green light, though this will depend on how Ofcom views the impact on media plurality.

As one of the key opponents of the BSkyB buy-up, the Telegraph wasn't planning to make life easier for Mr Murdoch when it embarked on its sting. To the outsider, its worst fear is now more likely. Complaints about the subterfuge pile up at the Press Complaints Commission, and what was supposed to be a major series exposing cracks in the coalition has become overshadowed by the story it decided not to print.

Robert Peston, the BBC's business editor, comes out of the whole affair as the real carrier of the sword of truth, even if the corporation opposes Mr Murdoch's purchase of its key rival, Sky. And Labour's leader, Ed Miliband, could have celebrated his birthday on Christmas Eve in the hope that he is back in the game. His soundbite about Lib Dems being passengers in the Tory government "locked in the boot" was good – though it looked better in print than on TV.

When the high-kicking of Westminster politics returns in the New Year, the Labour leader will go on the attack and seek to exploit further apparent divisions in the coalition. All ministers, but especially Lib Dems, had better not put a foot wrong.