Census 2011: 'Heavy metal's not music. It's a religion'

The preparation for next year's census is in full swing, but the jostling and politicking about who and what will be counted in the population survey is already causing serious headaches.

This time next year, every adult in England and Wales will receive a questionnaire for what is expected to be the longest and most detailed census ever conducted.

Costing £500m, it will paint a precise portrait of who and what makes up our nation – which is why a litany of special interest groups, from the serious to the absurd, are agitating for their vision of what the form should look like and which questions should be asked.

Sikh groups, for instance, want to be recognised as an individual race and not just a religion. And at the sillier end of the spectrum, heavy metal enthusiasts have begun an online campaign to get their head-banging music genre recognised as a religion. For analysts at the Office for National Statistics (ONS), meeting everyone's aspirations will be all but impossible.

A population census has been carried out in Great Britain every 10 years since 1801, except for 1941, during the Second World War. As the cultural and ethnic make-up of the country changed, so did the questions. Following devolution, separate surveys were carried out in Scotland and Northern Ireland.

In 1991, citizens in England and Wales were asked for the first time to describe their ethnic origin, with 16 options including a catch-all "other" box for those whose races were not included. Ten years later, respondents were asked their religious affiliation. But not everyone is happy with the way race has been categorised. People of Middle Eastern, Latin American or South-east Asian origin, for instance, have to tick the "other" box.

This week, the Sikh Federation will urge the ONS to include Sikhs as an individual race, after their community won a High Court battle in the 1980s to be officially recognised as a race under British law.

Jagtar Singh, a federation member, said the request was more than just a point of principle. "Information taken from the census is used by 40,000 government bodies to work out where resources should go and how they can be allocated," he said. "If Sikhs are missed off in 2011 we will have to wait yet another decade, perhaps longer, before we are properly recognised."

The ONS has said that because of financial constraints it will only be adding two ethnicity boxes to the census. It has yet to state what these will be but a test questionnaire three years ago included the terms "Arab" and "Irish traveller/ gypsy", suggesting that Sikhs may miss out this time around.

Mr Singh said: "We want Sikhs to be included for positive reasons but the Government looks set to collect data or Arabs and travellers to keep a closer eye on them."

Opposition MPs believe the census will be too expensive and intrusive. The shadow Cabinet Office minister, Francis Maude, said last week: "How can a cost of £500m, which is double the cost of the last census, be justified at this time of fiscal crisis?"

The Government hit back, saying a detailed census enabled future administrations to allocate money more efficiently, adding £700m to the economy. Others will no doubt use the census to cause mischief. In 2001, an online campaign launched by Star Wars fans encouraged people to list their religion as "Jedi" so that it had to be officially recognised. Parliament quickly changed the law – but not before 390,000 "Jedi" adherents signed up.

This year, social networking sites could throw another spanner in the works at the ONS. A Facebook group asking for heavy metal to be made a religion has attracted 14,000 members in two weeks. "It's not meant to offend anyone. It's just a bit of fun," said Alexander Milas, editor of Metal Hammer magazine. "But then again, maybe we are trying to make a point."