The UK retains a strong Christian heritage, according to the release of figures from the 2011 census. The first detailed breakdown of figures collected last year show changes in ethnicity, religion, marital status and home ownership - among others - across the country.

The figures show a 12 per cent decline in the proportion of people citing Christianity as their religious identity compared with the last census in 2001. Whereas 72 per cent of the UK labelled themselves as Christians on the first census for over a century which included the question, only 59 per cent declared such allegiance this time around. This was alongside an increase to 25 per cent of those citing no religion and a two per cent jump in the Muslim population.

It was the only question on the census which was voluntary, and more than four million people did not provide an answer. Respondents were also able to provide further details if they followed an alternative religion or expand on their 'no religion' response. 

The largest alternative religion cited was Jedi Knights, which followed a nationwide campaign in 2001 for it to be recognised as an official religion. Despite losing half of its adherents in the intervening 10 years, more than 176,000 claimed it as their identity, more than five times as many as specifically cited an atheist non-belief identity, which only attracted 29,267 supporters. The Heavy Metal religion founded in 2010 by Metal Hammer magazine also garnered support from 6,242 devoted fans.

There were significant differences across the country with Norwich and Brighton the local authorities with the highest non-religious population – 42 per cent in both. The Merseyside area had the highest Christian allegiance, with 81 per cent of the population in Knowsley local authority.

London local authorities had smaller Christian populations recorded in the census returns, but overall higher levels of religious belief; in seven local authorities there are more Muslims than those with no religious beliefs. Tower Hamlets had the lowest Christian population in the country, and the only area of the country with more Muslims than Christians.

The census results show the population of the UK is changing, and in particular the changes brought about through immigration - especially in the past decade - from the European Union. For the first time less than half of London is white British, and the significant population growth over the past decade is mostly attributable to immigration.

Questions remain, however, as to what extent the changes in religious identity accurately reflect changes in the religious beliefs and actions of the UK population. The question asks what religion you are and as such it is likely to attract a far higher level of support than those who regularly attend church or would consider themselves committed to Christianity.

Steve Clifford, general director of the Evangelical Alliance, said: "There’s no real surprise in these figures, they reflect what we are seeing across the country. Being a Christian is increasingly understood as following Jesus and not just wearing a cultural or historic label. For a lot of people who do not identify as religious, it is probably more taking off a label that doesn’t fit than embracing a particular anti-religious agenda.

"As evangelical Christians we are presented with a fantastic opportunity. The gospel prospers in a context where faith is alive and freely chosen; we should take the results of the census as an opportunity to get to know the people the numbers represent."

In the run up to last year's census the British Humanist Association ran a high profile campaign to encourage people to tick the no religion box, and there was a substantial increase in those not identifying with any religion. However, the increase was less than expected and some early reports suggested the Christian population could dip below 50 per cent. The census measures religious identity rather than belief or adherence to that belief, and therefore the numbers are far from an accurate measure. This is especially true at a time when many parts of the UK, especially London, are seeing growth in church attendance. Likewise, as new research from Theos suggests, many who do not belong to a religious group still have faith beliefs.

Nick Spencer, research director at Theos, said: "These figures show that we have a plural religious landscape but that doesn't mean we're atheist. Digging deeper, we see that even those who say they have no religion often have a variety of spiritual beliefs but they don't want to associate these to religious institutions."

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