He said: “What has been explosive is that his examples have referred to Sharia law, which is an emotive concept in our society.

“He is saying these Sharia councils in some places already exist informally.

“It might be better to formalise them under British law, to make sure they do correspond to British law. But there are real practical difficulties.”

He added: “It will take a great deal more thought and work before I think it is a good idea... The Archbishop has a way with language, but this was a very heavy lecture.”

Dr Williams said yesterday: “It seems unavoidable and, as a matter of fact, certain conditions of Sharia are already recognised in our society and under our law, so it is not as if we are bringing in an alien and rival system.

“We already have in this country a number of situations in which the internal law of religious communities is recognised by the law of the land as justifying conscientious objections in certain circumstances.

“There are ways of looking at marital disputes, for example, which provide an alternative to the divorce courts as we understand them.”

A spokesman for Prime Minister Gordon Brown said yesterday: “Our general position is that Sharia law cannot be used as a justification for committing breaches of English law, nor should the principles of Sharia law be included in a civil court for resolving contractual disputes.

“If there are specific instances like stamp duty, where changes can be made in a way that’s consistent with British law and British values, in a way to accommodate the values of fundamental Muslims, that is something the Government would look at.

“But the Prime Minister believes British law should apply in this country, based on British values.”

Former Home Secretary David Blunkett said people must not be excluded from the law because of cultural or faith reasons.

He told BBC Radio 4’s Today programme this morning that formalising Sharia law “would be wrong democratically and philosophically but it would be catastrophic in terms of social cohesion”.

The Rev Paul Dawson, spokesman for Reform - an evangelical group representing more than 1,000 parishes - said:

“From Reform perspective, the Archbishop’s comments are pretty disturbing and unhelpful and we long that he would give clear Christian conviction about Jesus Christ and how good it is to be Christian and give clear Christian leadership and we find it sad he does not do that.”

The Bishop of Hulme, the Rt Rev Stephen Lowe,  defended Dr Williams and said he was appalled at the “knee-jerk” reaction to a serious piece of academic work.

“We have probably one of the greatest and the brightest Archbishops of Canterbury we have had for many a long day,” he told BBC Radio 4’s World at One.

“He is undoubtedly one of the finest minds of this nation. The way he has been ridiculed, lampooned and treated by some people and indeed some of the media within this process, is quite disgraceful.”

The Muslim Council of Britain said it was grateful for the “thoughtful intervention” of the Archbishop on the discussion of the place of Islam and Muslims in Britain today.

“The MCB observes, with some sadness, the hysterical misrepresentations of his speech which serves only to drive a wedge between British people,” a spokesman said.

Dr Muhammad Abdul Bari, secretary general of the MCB, said: “The Archbishop is not advocating implementation of the Islamic penal system in Britain. His recommendation is confined to the civil system of Sharia Law and that only in accordance with English law and agreeable to established notions of human rights.”