It's easy to imagine the frantic discussions that were held between tax-dodging Jimmy Carr and his public relations advisers this morning.

"Look, Jimmy, this isn't playing out at all well. Don't turn it into a gag - just hold your hands up, say sorry, and hope it goes away." Or something along those lines.

Hence we have the headline on the BBC's news site this morning: "Comedian Jimmy Carr: I've made a terrible error over tax." He goes on to say sorry to everyone.

Well, of course he has. He's been caught with his trousers down in a Times expose. Otherwise, he'd still be happily engaged in a dodgy tax scheme while making a very nice living cracking jokes about "fat cat" bankers who avoid tax.

He's got tickets to sell for a nationwide tour, which includes a date at Middlesbrough Town Hall in November. A Carr u-turn was the only way forward.

He's not alone in his grubby dealings, of course. Members of Take That are also accused of doing something similar.

David Cameron has declared it is morally wrong but crucially adds: "There is nothing wrong with people planning their tax affairs to invest in their pension and plan for their retirement - that sort of tax management is fine."

Mmm. "Tax management." There's an interesting phrase. Could it be a case of Mr Cameron leaving himself a defence for when it inevitably emerges that some of his friends are involved in varying levels of "tax management".

If the Prime Minister thinks this murky world of tax avoidance is morally wrong, what is he going to do about it? He has the power to make what Jimmy Carr did not just morally wrong but illegal.

So come on, Mr Cameron, let's see some action to stop rich people fleecing the rest of us.

As for Jimmy Carr, I wonder if the apology is going to be enough. There's been no mention so far of coughing up any of the money he's immorally shoved under the cushion in the Channel Islands.

He doesn't have to, of course, because what he did isn't illegal - yet. But he does have a lucrative career to rescue.