The Office for National Statistics has spoken to PinkNews.co.uk about why it does not propose to ask a question about sexual orientation in the 2011 Census.

Earlier this week gay equality organisation Stonewall joined forces with the Trades Union Congress to press for the inclusion of such a question.

The Census is conducted every 10 years by the ONS and every household in the UK is legally required to fill out a census form.

A spokesman for the ONS told PinkNews.co.uk that they do not propose to ask a question in 2011 as they feel there are better ways to collect “timely and reliable” sexual identity information.

“In a survey environment information will be supplied by the person to whom it pertains and will not be shared by other householders,” he said.

“Privacy and confidentiality were the key concerns expressed by both the lesbian, gay and bisexual and heterosexual groups in the focus group testing.”

Census forms are filled out by the head of the household and not by individuals who live there.

ONS is developing and testing a question that can be used on social surveys that could be added to other ONS surveys, such as the Integrated Household Survey.

ONS has tested different versions of the sexual identity question.

The spokesman said:

“If, as planned, the question(s) were asked from 2009 onwards in a large household survey such as the IHS, baseline prevalence estimates will be available about three years earlier than 2011 Census counts.

“Survey estimates can be updated annually, enabling regular monitoring of the size, distribution and changing social-demographic profile of the LGB population.”

Unlike the Census, the IHS is not compulsory and does not cover every household in the country.

The ONS Sexual Identity Project was established in 2006 to “meet user requirements” for information on sexual identity.

Expected to report next year, it has consulted with groups made up primarily of representatives from different government departments, LGB groups and academics and researchers with experience in this field.

“ONS has agreed with the project’s user/stakeholder group and expert advisors that the concept which should be measured is sexual identity, rather than other dimensions of sexual orientation such as attraction or behaviour,” ONS told PinkNews.co.uk

“It is the dimension most relevant to the intended uses, which include identifying discrimination and disadvantage due to sexual orientation.

“Focus groups with heterosexual, gay/lesbian and bisexual members of the public have explored people’s conceptualisation of sexual identity, the language and terminology they use and understand, the acceptability of asking about different dimensions of sexual orientation on general social surveys, and how the question should be administered in face-to-face survey interviews in the household environment.”

The lack of a question on the Census has led to other social research organisations to exclude questions on sexuality, often citing the lack of a standardised question.

Most noticeably, the British Crime Survey fails to ask respondents about their sexual orientation, despite government and police initiatives around homophobic crime.

It has already been confirmed that there will be an option to record civil partnership alongside marriage on the 2011 Census.

Final decisions on the content of the 2011 Census will not be made until the consultation and testing programme is complete and Parliament gives formal approval in 2010.

A White Paper setting out the Government’s proposals is scheduled for the autumn.

Last month it was revealed that just one in 100 people described themselves as gay in a recent ONS survey into British sexuality.

A further one in 100 described themselves as bisexual, 0.6 per cent said “other” and three per cent said they were not willing to declare their sexuality.

Some failed to to answer the question properly; responses included: “female”, “normal”, “not active” and “I am OK with my sexuality.”

ONS asked 4,000 people but admitted that the results of the survey were “not a reliable estimate” of the gay population.

Last year Stephen Williams MP tabled an Early Day Motion in the House of Commons asking the government to ensure that a question is asked in 2011 about sexual orientation.

Mr Williams, the MP for Bristol West, welcomed the decision to ask a question about civil partnerships, but said that is important to know how many gay people there are in the UK.

“There will always be some dispute as to the proportion of people that are gay, lesbian or bisexual – is it 5%? 8%? 10%?

“It is important that the make-up of society is understood.

“I do not buy this argument that this is not a suitable question for the census, every census since 1901 has added questions – we now ask people about their race and even if people are white and Irish.

“In 2001 I wrote onto my census form that I am Welsh, because there was no way of recording that as I live in England, and that I am gay. “

Mr Williams told PinkNews.co.uk that some reluctance to answer questions on sexual orientation could be overcome by making people aware of how census data is used:

“I can understand that some people will be reluctant to disclose, but information about individuals is secret for 100 years and it is only the aggregate statistics that are published

“There is a risk of under-reporting, but a PR campaign by ONS and campaigning groups to encourage people to register would counter that.”