The General Secretary of the Trades Union Congress Brendan Barber has joined with gay equality organisation Stonewall’s chief executive Ben Summerskill to ask for questions on sexual orientation to form part of the census.

The next national survey will take place in 2011.

It is conducted every 10 years by the Office of National Statistics (ONS), who announced last year that they did not think a question about sexual orientation would not be suitable.

The TUC and Stonewall believe that excluding sexual orientation data places LGBT groups at a disadvantage, as local authorities don’t have an idea of numbers of LGBT people in their communities when they are allocating resources for services.

A spokesman for the ONS said:

“The Office for National Statistics recognises that there is some user demand for information on sexual identity but considers that the census is not suitable for collecting information on sexual identity for the first time.

The main priority for the Census is an accurate headcount.

“There are significant concerns about privacy and acceptability and the effect that such a question could have on the overall response.”

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.

“A question on sexual orientation would help to monitor equality legislation and improve service provision to lesbian, gay and bisexual people,” his motion reads.

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. “

The ONS said:

“The General Register Office in Scotland has carried out a small scale postal survey which included a question on sexual identity.

“However, this produced a very low overall response rate and a very high proportion of people who did not provide useful data on sexual identity, either by ticking the ‘prefer not to answer’ box or by declining to complete the question at all.”

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.”

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 autumn 2008.

“We are looking at the feasibility of including the question (or questions) on ONS social surveys, to allow for estimates of the size and characteristics of the lesbian, gay, and bisexual (LGB) population to be produced,” said an ONS spokesman.

“We are consulting on this with government and non-governmental organisations, including representatives from LGB groups.”