Instead of the cultural relativism he promoted while in office, Phillips now advocates “muscular integration”. As examples of this, he suggests regulating sharia courts and obliging them to sit in public; preventing Islamic control of school governing bodies, as in the Birmingham “Trojan Horse” scandal; exposing “silence-for-votes” deals between local politicians and Muslim leaders, as in Rotherham and Rochdale; and stopping the Salafist takeover of mosques, funded by Saudi Arabia and the Gulf states.

Such moves would indeed be welcome, but they do not go far enough. What is missing is a deeper understanding of the threat posed by radical Islam to the values that underpin British society. In an important new book, Faith, Freedom and the Future (Wilberforce, £12.99), Michael Nazir-Ali draws on his articles in Standpoint since 2008 to explain how “radical Islamism cannot be effectively opposed without reaffirming the Christian foundations and values of this nation which gave us Magna Carta and the liberties that flowed from it”. Bishop Nazir-Ali, himself born in Pakistan, knows Islam, its theology and its politics extremely well. He asks: “Does the logic of Islam lead ineluctably to Islamism with closed, regressive and monolithic societies as the radicals desire, or can it also lead to open, free and plural societies?” This has become an urgent question, not only for Muslim countries, where minorities struggle to survive, but also for Western ones which, like Britain, are now confronted by the rise of political Islam in their midst. Will we allow our cities to become miniature Islamic states?

Here in London, which is home to about a third of British Muslims (including thousands of migrants who live below the radar of the authorities), we have already seen the assertion of power by political Islam. The takeover of Tower Hamlets by a corrupt Islamist politician, Lutfur Rahman, may be a harbinger of things to come. Last year he was removed from office by special commissioners, but for five years Rahman and his cronies ran a borough of nearly 300,000 people, distributing a budget of more than £1 billion. It is worth noting that after being ousted from the Labour Party, he was able to replace it with a notionally “independent” but in practice sectarian group, even though Muslims officially make up only a third of the population. The Muslim “block vote” is such a formidable electoral force that for Islamists to dominate a city it does not need to have a Muslim majority.

The greatest prize, of course, is London itself. By the time you read this, the capital may already have elected the first Muslim Mayor of London: Sadiq Khan. At the time of writing, polls predict that Khan, who is also Labour MP for Tooting, will win by a larger majority than either of his predecessors, Ken Livingstone and Boris Johnson.

Khan has worked hard at projecting a moderate image as a modern, liberal Muslim with no sectarian baggage. He no longer protests, as he did in 2004, that Sheikh Yusuf al-Qaradawi perhaps the most influential preacher in the whole Islamic world — is “not an extremist”. (The Sheikh says that Hitler “put Jews in their place”.) He has carefully distanced himself from Babar Ahmad, who was later convicted of terrorist offences, and other extremists with whom he was once associated. But he knows very well how important the Muslim vote is for Labour. At least ten London boroughs have large, mainly conservative Muslim communities, where children grow up in an Islamic monoculture and women are covered or veiled. Khan is not likely to challenge the self-appointed leaders of these communities. At all costs, he must maintain Labour’s near-monopoly of Muslim politics and prevent the emergence of an explicitly Islamist party.