Philip Hensher: Lembit, the Cheeky Girl and a Lib Dem conspiracy

Ever since Wilson gave the Beatles MBEs, the coming together of politics and celebrity has inspired fear

It's difficult not to start developing conspiracy theories about a recent twist in the history of the Liberal Democrats. Surely, this one must have been planned by a powerful but invisible cabal in the senior ranks of the party. To recapitulate: Mr Charles Kennedy, darling of the chat shows, had to resign as leader of the party after developing a drink problem. Candidates for the prize of leadership of the party, initially a promising-looking field, fell away rapidly: male prostitutes did for one, implausibly pretending not to be gay for another, and being generally unknown for the third.

The man who was left at the end of this rather unconventional process was a Sir Menzies Campbell, an elderly Scotsman best known in the House of Commons for his general sprightliness and willingness to pronounce his own name in rather a silly way.

Since then, the party has been regretting having mistaken age for experience and ability. Sir Menzies' performances at Prime Minister's Questions have been reliably terrible - last week, all he could produce as a soundbite over the Ipswich murders was "will the Prime Minister consider having a wholesale review of the law in this area so as to make sure that we do everything in our power to ensure women's safety?"

Calling for wholesale reviews is never going to win anyone's vote, and the once-promising Liberal Democrat share is falling steadily. The solution, to the conspiratorial cabal, would have been obvious. If the party was popular while its leader was appearing on Have I Got News for You, then some vital connection had been lost with the young. Something had to be done.

It has just been announced that Mr Lembit Opik, one of the most personable of Liberal Democrat MPs, has moved from one celebrity relationship to another, rather more startling. Mr Opik has been engaged for four years to Sian Lloyd, the much-loved television weather presenter, though recently she has said that she found his hard-partying lifestyle difficult to deal with - their first date was at the Proms.

He has shown signs of distinct personality; a keenness on paragliding came to an end with a near-fatal accident in 1998, which broke his back in 12 places. He has appeared not only on Have I Got News for You, that talisman of modern political success, but also, with Miss Lloyd, on Celebrity Who Wants To Be A Millionaire?. On that, they won £64,000 for charity.

It's true that he also has a most unfortunate record in backing the wrong horse, supporting, in turn, Charles Kennedy, Mark Oaten and finally Simon Hughes in the leadership contest. But there must have seemed to be a distinct aura of glamour about Mr Opik; the perfect channel through which to appeal to that elusive young voter. If only there were some way to throw one of the most popular singing stars of a generation in Mr Opik's path ...

Of course, there is no reason to think this latest development is planned for psephological reasons, but it does seem somewhat convenient. Mr Opik, it has just been announced, has left the saintly Miss Lloyd and is now in a relationship with Miss Gabriela Irimia. She is one of the Cheeky Girls - I'm afraid I can't tell you which one, but possibly the one who stands on the left. He said: "I continue to regard Sian as one of the brightest, most outgoing, hard-working and generous people I've had the privilege to know." Miss Lloyd, not used to being patronised in such a way, said she was going to keep the ring - "After all, I wouldn't like to see it on the finger of a Cheeky Girl."

At first sight, they might not be thought to have an enormous amount in common. Miss Irimia rose to fame through failing to progress beyond the first round of Popstars: The Rivals and being asked by a judge if she were actually a man in drag. Mr Opik rose to fame through his career as a personnel manager at Procter & Gamble and winning the constituency of Montgomeryshire in 1997.

Her most famous public utterance is: "Every girl and boy needs to grow up/ To enjoy the fun in disco clubs", or possibly: "Come and smile, don't be shy/ Touch my bum, this is life". His biggest hit to date, on the other hand, has probably been the well-known: "We are not seeking to gerrymander the formula in favour of Wales; rather we are trying to ensure that it is fair to Wales - and, for that matter, to Scotland and Northern Ireland - by it being needs-based."

Unkind people might suggest that only in the upper ranks of the Liberal Democrats would the Cheeky Girls be seen as forming that vital connection with urban cool. Others, more generous of spirit, would certainly dismiss any thought of planning. Certainly, when they met at a party for Channel 5's All Star Talent Show ("Mr Opik played harmonica while Gabriela and her sister Monica attempted ballet", one newspaper breathlessly reported) love blossomed immediately. Their first date was to the Science Museum.

Well, we all wish Mr Opik and Miss Irimia well; they seem, both of them, like cheery, hard-working people, and it's not really for us to guess what on earth they might have in common. Nevertheless, ever since Harold Wilson gave the Beatles MBEs, the coming together of politics and modern celebrity has inspired fear and terror in the general population. Let's hope that at no future point will the Cheeky Girls be wheeled out in front of a conference audience, and, going into a little dance, invite the massed Liberal Democrats to touch their bums.