One of things that surprised me when I was in Iran was to find out that the country finances seven times as many sex change operations as the entire European Union. And the reason for that is because Ayatollah Khomeini himself, in the early 1960s, in the same time that he was developing this other idea of an Islamic state, also hit upon the idea that if a person is born into the wrong sex, it was entirely proper for them to change sex.

Whenever one writes a book one should have a notional reader in mind.

My father's from Pakistan and he has been a secularist all his life. In the Pakistani context, there's no messing with religion. There's been a battle for the soul of Pakistan since 1947 and I have grown up without any illusions about the dangers of religious power in the context of a country like Pakistan.

Ayatollah Khomeini issued a fatwa to that effect, which was then given effect in the Islamic Republic of Iran, so in the Islamic Republic of Iran, it's flexible enough to allow for sex changes, and it encourages sex changes. But if you want to change your religion in Iran, you've got some serious problems. There are other problems. You're allowed to change sex, but if you want to be a homosexual, theoretically at least, you face the death penalty. Quite how often these penalties are carried out is a moot point, but it's there on the statute books.

I spoke to my father - my father's from Pakistan and he's also a lawyer - I said to him, "Well what does the Shari'a say?" And he said, "Well, of course it doesn't justify suicide bombs," but he didn't seem to know where the Shari'a came from or what it was all about. The more I asked people in my family as well as friends, the more I realized that there seemed to be widespread ignorance in the Muslim community. And that's something which I actually found to be the case over the next two and a half, three years I spent writing the book.

People are coupling and decoupling all the time in Great Britain. The fact that Muslims choose to precede it with a certain formula of words, shouldn't bar them from anything. But, no one's saying that polygamy should be institutionalized in this country. That Muslim's uniquely should be allowed to have two or three or four marriages.

Shari'a is not just the Qur'an, you see Shari'a is comprised according to all the doctrines. There's consensus and analogy - argument by analogy. These are the four components in the Shari'a. An orthodox Sunni would not accept that the Shari'a was simply comprised of the Qur'an itself and actually there are people who say that it's heretical to believe that. They have to say that because if they don't say that then they would have to accept that, for example, stoning is not a punishment which appears in the Qur'an - it doesn't.