English law is rooted in the Judaeo-Christian tradition and, in particular, our notions of human freedoms derive from that tradition. In my view, it would be simply impossible to introduce a tradition, like Sharia, into this corpus without fundamentally affecting its integrity.
The Sharia is not a generalised collection of dispositions. It is articulated in highly concrete codes called fiqh. It would have to be one or the other, or all, of these which would have to be recognised. All of these schools would be in tension with the English legal tradition on questions like monogamy, provisions for divorce, the rights of women, custody of children, laws of inheritance and of evidence. This is not to mention the relation of freedom to belief and of expression to provisions for blasphemy and apostasy.
We should learn from the debate on this question which recently took place in Canada. Here it was mainly Muslim women’s group that succeeded in preventing the application of Islamic law in matrimonial matters. The importance of a single law for all was strongly re-affirmed.