I mean well, I assure you. I know that most of you are happy to accept this assurance. You’re so nice, honestly you are. But there may be a small minority among you who aren’t convinced. And if you are one of them, I can only repeat – I mean well.

I am talking about the Liberal Democrats. You see, I am about to offer the supporters of that party some political advice. The problem is that they might not want to take it, coming as it does, from me. Because the Liberals and I, well, we’ve got history.

Most of you adopt what one might term a passive-aggressive stance towards the Liberals – refusing to pay the slightest attention to anything they do, just for example. I went far, far farther than that.

As an ally of the former SDP leader David Owen I took fighting the Liberals so far that I eventually found myself tramping round the streets of the Vale of Glamorgan promoting a by-election candidate who couldn’t understand any policy and had a spare tooth in his top pocket that he only put in for press conferences. And all just to stop the Liberals getting in. There is a nice Yiddish word for what I was – meshugener. It means lunatic.

So I’ll excuse the Liberals for wanting to shoot the messenger, rather than listen to the message. But what I am about to tell them it really is in their best interests to heed.

Guys, Ming Campbell has got to go. Now. Shut the door behind you, Ming.

This is not a practice drill. Let’s begin with a cold hard look at the position. Amid all the ink spilt writing about the Brown bounce and the Cameron crunch, one thing has been missing from the coverage. Ming. The driving force in British politics is the uselessness of Ming. What makes the gap between the big two parties go up and down is simply the identity of the party to which the Lib Dems and their hopeless leader are losing votes on any given day.

Throughout the last Parliament the Lib Dems averaged more than 22 per cent and scored 22.7 per cent on election day. When David Cameron became Tory leader the Liberals fell to 18.3 per cent. And since Gordon Brown became Labour leader they have averaged 16 per cent. In other words, Ming Campbell now presides over a party that has lost 30 per cent of its support. Journalists on The Times are discouraged from calling grave situations a crisis. This is a crisis.

And they won’t emerge from it until they get a new leader.

Now this may be monstrously unfair. Sir Menzies has his fans, who describe him as courteous, thoughtful, intelligent. I am willing to believe it. I’ve nothing against the man. But fair isn’t the point. There is a wonderful moment in the film The Fugitive where the escaped prisoner, Harrison Ford, is being pursued by the cop, Tommy Lee Jones. “I didn’t kill my wife,” protests Ford. “I don't care,” replies Jones. When friends of Ming plead his case, “I don’t care” should be the tough, unyielding reply of Liberals who want to win seats at the next election, not lose them.

For Ming just doesn’t work. He sounds and looks feeble and past it. His Commons performances are weak, his television soundbites limp. He hasn’t given his party any sense of direction. When Gordon Brown tried to mug the Libs by putting Paddy Ashdown in the Cabinet without offering policy concessions, Ming said he needed to think about it overnight. He has got to go.

And anyone who isn’t a signed-up Lib Dem activist can see it. Indeed, most of the signed-up activists can see it too. At the last election the Lib Dems pushed the Tories into third place among the under35s. Now the Tories are 7 per cent ahead among this group.

There are, of course there are, arguments for keeping Ming. But not one of them really stacks up.

The first is the idea that Ming will come good. When people get to see Ming in the election campaign they will take to him. Oh. No. They. Won’t.

The Liberals are convinced they get a bounce during the election campaign. Careful study of polling suggests that this is largely a myth. Even if it wasn’t, in Ming’s case repeated appearances on television will only make things worse.

The second, and by far the most serious, argument against deposing the Lib Dem leader is that he won’t go quietly and it would be unthinkable to push him out. Much too messy and embarrassing, especially as it would be the second time in a single Parliament.

This is an understandable concern. But it’s also wrong. When you fight as hard as the Lib Dems do for the smallest scrap of media attention, it must be very tempting to believe that when the attention comes, it actually matters. It doesn’t. If the Lib Dems had enough money to pay for focus group research they might stop fighting so hard for coverage, because they’d realise how little attention voters are paying and how poor their recall is. I guarantee you, my Lib Dem friends, that weeks of television news broadcasts featuring arguments about your party will entirely pass voters by. Remarkably few people will shout through to the kitchen: “Hold dinner for a moment, love, Sarah Teather’s on.”

Who you end up with as leader, though, that does matter. Installing either of the credible alternatives to Campbell – Nick Clegg or Chris Huhne – would be easily worth the pain of making the change.

Then there’s a final argument. Yes we should do it, say the Libs, just not now. Gordon Brown may call an election. Well, yes, he might. That’s why you can’t afford to hang around. You need to act now. In fact, there’s an irony. The only reason Mr Brown can even think of an election is that Ming has meekly surrendered so many Lib Dem votes to him. Want to stop him? Get a new leader.

It’s too hard? It’s too difficult? It’s not the moment? You can’t do it to him? He’s a decent sort? Fine, then go ahead and lose. See if I care.

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