The turbulent priest is back to cause more trouble for the government. In his initial statement on the St Paul's protest, Rowan Williams pointedly noted that "the urgent larger issues raised by the protesters ... remain very much on the table". His thoughtful article in today's Financial Times is an attempt to address them.

Lamenting that there has been "little visible change in banking practices" since the crisis, the Archbishop calls for a Tobin tax on financial transactions as a part of a series of measures to reflect "the moral agenda" of the protesters. It is a welcome and long overdue recognition that, whether or not one agrees with their tactics, the protesters' cause is just. As Williams writes, their protest has been welcomed "by an unexpectedly large number of people as the expression of a widespread and deep exasperation with the financial establishment that shows no sign of diminishing". At the same time, he concedes that many of their demands are "vague", insisting: "it is time we tried to be more specific".

With this mind, he sets out a three-point programme, largely based, in an act of ecumenicism, on the document published by the Pontifical Council for Justice and Peace. Williams calls for "early government action" to separate retail and investment banking, for the creation of an obligation for banks to "help reinvigorate the real economy" and, most strikingly, for a "Robin Hood Tax" on financial transactions. His intervention is significant not least because, as City AM reveals today, George Osborne, despite his protestations to the contrary, is minded to oppose a Tobin tax even if it is applied globally. In a private letter to bank chiefs, the Chancellor wrote: "I agree there would need to be further discussions about whether any FTT model offers an efficient mechanism to raise revenue."

It is not, you sense, a view that Williams has any sympathy with. He writes:

The objections made by some who claim it would mean a substantial drop in employment and in the economy generally seem to rest on exaggerated and sharply challenged projections - and, more important, ignore the potential of such a tax to stabilise currency markets in a way to boost rather than damage the real economy.

Williams's article, like his coruscating New Statesman leader earlier this year, will trouble some conservatives. But it would be absurd for the leader of the Anglican communion not to respond to a protest that raises urgent questions of fairness and social justice. As it has before, with the 1985 publication of Faith In The City, an excoriating critique of Thatcherism, the Church should lead the debate. Williams's article is an admirable attempt to do so.