Doing God: Why is Cameron calling himself ‘evangelical’?

Easter has done something odd to the prime minister.

Last week he said his moments "of greatest peace" came when he attended eucharist in a Kensington church. He pointedly made reference to "our saviour" throughout.

Now he has published an article in the Church Times in which he calls on Britain to be unashamedly "evangelical" about its faith and described it as a "Christian country".

It comes a week after local secretary Eric Pickles called on secularists to stop preaching "politically correct intolerance" and "get over" the fact Britain is a Christian country.

Both men are plainly right that Britain still has no separation of church and state and retains Christian institutions.

But in the broader sense, their insistence that Britain remains a Christian country is difficult to stand up. Churches used to point to the 72% of people who described themselves as Christian in the 2001 census. That became more difficult when the 2011 census showed just 59% of England and Wales identified themselves as Christian.

That figure is almost certainly an over-estimate. We know that people who tick Christian on the census have a very broad assessment of the word, which involves history and cultural identity. The census is also problematic because one member of the family typically fills it in for everyone. Surveys, on the other hand, are usually filled out individually, giving a more nuanced view.

When the question is more strictly worded, the numbers reduce substantially.

The 2009 British Social Attitudes survey asked: "Do you regard yourself as belonging to any particular religion?". 50.67% of respondents selected 'no religion'. A YouGov survey from 2012 found 76% were 'not very religious' or 'not religious at all'.

So who is Cameron appealing to?

Not so long ago the prime minister took a witty approach to his faith which seemed to chime much more naturally with British religious sentiments than his current rhetoric. He once described his faith as "like Magic FM in the Chilterns" – fading in and out.

Now he has markedly shifted in tone, adopting an 'us' and 'our' manner of speech and using words like 'saviour' and evangelical', which sound more at home across the Atlantic than among the more relaxed standards of British religious discourse.

Everything the prime minister does between now and polling day 2015 is about winning the general election, in an unusually tight race. That is the prism to look at his newfound religious approach.

For this, he must drag back as many naturally-Conservative voters as possible, shoring up his support against Ukip and bolstering the party for the fight ahead.

Cameron is attempting to appeal to those most outraged by same sex marriage – the most conservative element of the Church of England who could be tempted by Nigel Farage's more reactionary political offer.

At the same time Cameron tries to appeal to the more progressive elements of the church, which he has alienated with austerity and welfare reform. He dedicates extensive passages of his Church Times article to defending his decisions in language church-goers will understand.

Finally, he reiterates the broader argument – accepted by most religious people – that faith is being swept out of the public sphere by a new 'militant atheism' which insists on firm secular standards.

The appeal suggests Cameron has a religious problem, or at least that he believes he does.

He is blamed by the religious right for gay marriage, by the religious left for welfare reform and by most people of faith for the sneaking suspicion he has failed to stem the tide of secularism in British society.

The Church Times article suggests he intends to rectify that problem, but he will need to tread carefully: what appeals to one side of the church may not appeal to the other.

There is another, more substantial danger. The British public will be wary of religious rhetoric from a prime minister – especially if it seems it is being used for political advantage.