Brown should make life hell for the tax havens

And if it's not the non-doms, it's those who claim not to live here, flying in and out for fewer than 90 days a year but still managing to run vast enterprises in the UK. Then it's the ones who do reside in the UK but put the business in their partner's name and the partner is holed up overseas.

My senior tax partner friend at one of the leading City law firms describes these as the most common "structural" ways of avoiding tax. Structural! Judging from the simplicity of my pay packet, where there's a top figure followed by a much-reduced figure, my own structure is too damned simple.

If nothing can be done about them - and I'm the first to concede that cracking down on non-doms may do London's position as a global financial magnet immense harm - then surely it is time to crack down on the tax havens.

We've a perfect excuse as we continue to fight the war against terror. We're also combating the drug barons and organised-crime. We want to do something about poverty in Africa. Those international financial pariahs, the hedge funds, are also fond of hiding behind nameplates in locations in the sun.

We can no longer turn a blind eye to places that specialise in stashing cash and fostering money-laundering. The offshore centres will say how much more co-operative and transparent they are these days - to which I say nowhere near enough.

Their grip has been brought home most tellingly by Northern Rock - the Newcastle bank's huge Jersey-based fund is not being nationalised, and has first choice over the best of the mortgage book.

I'd like to think we're pursuing the same policy as the Germans and that we're prepared to stop at nothing, including buying bank records, in the pursuit of tax dodgers. The uproar the German BND intelligence agency has provoked in Liechtenstein, where it's got hold of details of more than 700 clients of the principality's LGT bank in return for £3.2 million, and in neighbouring Switzerland is a joy to behold.

The Swiss have complained the BND's activities are reminiscent of the Gestapo. Would this be the same Gestapo that hoarded its own looted treasures in Swiss bank vaults during the war?

But paying informants to provide bank statements doesn't get to the heart of the problem. Angela Merkel, the German Chancellor, is threatening Liechtenstein with isolation.

We should follow suit - but we shouldn't stop there. Governments should get together to co-operate and agree a policy of slow suffocation across all jurisdictions that promote virtually non-existent taxation and total secrecy. World leaders can do it on other issues, most recently the global credit crunch, so why not on something that affects them all, where it hurts, in their pockets?

If the sort of sanctions that were imposed by the US on Cuba were applied to Monaco, the Channel Islands, the Isle of Man and the rest if they refuse to open up their accounts and harmonise their tax systems, they would quickly succumb.

For it to work, it needs the drive of an ambitious politician - one who wants to make a name for himself on the world stage. Like the future leader from Scotland who once told the Labour Party conference: "A Labour Chancellor will not permit tax reliefs to millionaires in offshore tax havens." Someone, in fact, like Gordon Brown.