The US government may claim that the 2010 Census “will be one of the shortest and easiest to complete since the nation’s first census in 1790,” but it will also be the first to exclude legally married couples.

Gay marriage has been made legal in the US states of Massachusetts and California since the last census in 2000.

However, the US Census Bureau announced last week that while there will be the usual questions on gender, age, race, ethnicity, relationships and home ownership, any same-sex couple who report they are married will be reclassified as unmarried partners.

Democracy pressure group People For the American Way has started an online petition.

“Such “editing” would not only be highly offensive, it would lead to the reporting of inaccurate demographic data, completely contrary to the Bureau’s mission and goals,” it reads.

“Politics should have no place in the Census. Accuracy should be the only criterion.

“Legally married same-sex couples who report themselves as such should be counted that way.”

Documents released by the Bureau said that the following question will be asked in 2010 about relationships.

“The census subject about relationship is essential for classifying the population into families and other groups,” the document states.

“Information about changes in the composition of the American family, from the number of people living alone to the number of children living with only one parent, is essential for planning and carrying out a number of federal programmes.

“In federally funded nutrition and education programmes, how the money is spent hinges, at least partially, on census data about relationship.”

People For The American Way President Kathryn Kolbert said:

“It’s a fact that can’t be ‘edited’ out of existence. It’s time to stop faking the data for the sake of people who want to pretend that same-sex married couples don’t exist.”

In the UK, the Office for National Statistics does not propose to ask a question about sexual orientation in the 2011 Census.

However, there will be a ‘civil partnership’ option on the census, which is conducted every 10 years by the ONS. Every household in the UK is legally required to fill out a census form.

The Treasury estimates that 6% of the UK population are lesbian, gay or bisexual.

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.

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.

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 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.”