You'd have thought an idyllic island, a 'British Crown Dependency' off the coast of France with an average income of more than $50,000, must be a blissful place to live. Well, with 89,000 people and a notional $250 billion in the banks (that's almost $3 million per head), it better had be.

But Jersey, one of the world's leading tax havens – or 'secrecy jurisdictions' – isn't quite like that. It never is. I'm told that local groups have been fighting against the tax avoidance industry 'in a climate of fear and intimidation'. A quarter of the population lives in poverty. So that's what the off-shore City of London is really like. Perhaps we got just a whiff of it from the very nasty and on-going Haute de la Garenne children's home scandal.

Anyway, by a happy coincidence, a posse of campaigners and the incomparable Tax Justice Network will be joining local groups for a guided tour of the havens, a public fresh-air meeting and perhaps even a bit of overdue fun in Jersey on 12 and 13 March – just as finance ministers gather in Sussex, England, to prepare for the big G20 meeting in London on 2 April.

Since the easiest political trick in the book at the moment is to blame bankers and tax dodgers for everything, if the G20 meeting doesn't come up with some pretty clear proposals for tax justice on 2 April it will have been a complete waste of time. After all, who's going to pay those mounting tax bills? Britain provides more tax havens than anyone else, and Gordon Brown will be presiding over the G20 in London, so it should be a shoo-in.

Of course it won't be – and the G20 itself has no legitimacy at all. So it's just as well that Put People First has brought together the biggest coalition of social movements in Britain since Stop the War, for a demonstration on 28 March – and the World Social Forum meeting in Belém, Brazil, in February declared this a Global Day of Action.