Back in 2003, with the illegal Iraq war looming and protests filling the streets of London in opposition, Vanity Fair’s David Margolick came to Downing Street to interview Tony Blair.

When the writer broached the topic of religion – to US politicians what bees are to honey – the former PM’s spin doctor Alastair Campbell interjected sharply: “We don’t do God.” Of course, privately, Blair held a deep Catholic faith and never obscured it but there was a feeling among his advisors that in an increasingly secular Britain, spirituality was bad for business.