IAIN Duncan Smith has recast himself as the Ha Ha Bonk Man. To explore his new image, you need to dip into a children's joke book.

There you will almost certainly find a joke which runs like this: "What goes ha ha bonk?" Answer: a man laughing his head off.

Mr Duncan Smith's surprising conversion to hilarity occurred last week while talking to John Humphrys on the Today programme. During the interview, the Tory leader started laughing like the stiffer sort of hyena.

Asked whether or not he ran "a modernising party", he said: "No. What we are is a party that offers an alternative to Labour."

This was when the self-coined Quiet Man revealed his new identity. Asked about the gaping divisions in his party, Mr Duncan Smith reeled off a devastating speech worthy of Winston Churchill. Of course, he did no such thing. Instead he went: "Ha, ha, ha, ha."

Quizzed about the virulent bother within Conservative Central Office, caused by the sacking of his chief executive and the promotion of a hard right-winger, Mr Duncan Smith again resorted to: "Ha, ha, ha".

Listening at home, all I could do was worry that perhaps the Conservative leader wasn't feeling well. His laughter was dry and without humour. He sounded awkward, bizarrely off his game - and not at all like a man in charge of one of our most important political parties.

Now at this point you may be tempted to pause for breath. But, yes, I did just write "one of our most important political parties". I spent years hating the rotten bunch. And, yes, it is still tempting to dismiss the Conservative Party as a joke; more tempting still to wonder if Mr Duncan Smith had just got the joke, hence that strange barking cough that turned out to be laughter.

In the past this would have been another excuse to experience merriment at the expense of a political party that ran the country for far too long, messed up so many aspects of our national life - and, in 1997, got what it deserved: a good electoral thrashing.

Yet two Labour landslides and a deeply useless Tory party later, the situation looks less rosy. Indeed, the continued weakness of the Conservative Party is now a great worry. Parliament and politics suffer because of such an enervated opposition.

We have passed through oddly unbalanced times, with a preternaturally strong prime minister and a puny opposition, to arrive in these strange and unsettling days.

A popular premier is trying to drag a reluctant country - along with many in his own party - into a deeply unpopular war. And what do we have at the other end of the pitch? A weak, divided opposition that can't keep a sometimes arrogant government in check. A bedraggled, useless side led by a captain who thinks it's a good idea to go on the radio and laugh his head off.

This is not a healthy place to be. The Liberal Democrats have stepped up to give the Government the occasional tap on the nose, but they are perhaps not up to doing the job full time.

Our system works best with a strong Government pitted against a forceful Opposition. What we've got now is a walkover. And you can't help but worry that we're the ones being walked all over.

So before we get used to the footprints decorating our clothes, we should hope that the Tories sort themselves out. They don't need to win an election or anything alarming like that.

But they could make a start by disposing of the Ha Ha Bonk Man.

Updated: 10:46 Thursday, February 27, 2003