An analysis of poverty among lesbian, gay and bisexual Americans is to be presented to Congress next Friday.

Produced by the Williams Institute at the UCLA School of Law, the survey has been described as the first of its kind.

Its authors have said it undermines myth of gay affluence and demonstrates that lesbian, gay and bisexual citizens are as likely, or more likely, to be poor than heterosexuals.

They added: “Because the U.S. Census Bureau does not explicitly ask questions about sexual orientation, LGB families have been invisible in poverty statistics.

“This first analysis of the poor and low-income lesbian, gay and bisexual population reveals that LGB adults and families are as likely – and, in the case of some subgroups, more likely – to be poor than their heterosexual counterparts, contrary to the popular myth of gay and lesbian affluence.”

The review will include a discussion of the social and political factors that may lead to higher rates of LGB poverty, including vulnerability to employee discrimination, inability to marry and higher numbers of those who are uninsured.

This week, it was reported that the next US census, to be carried out next year, will not ask about sexual orientation or recognise gay marriages, civil unions and domestic partnerships.

The federal Defence of Marriage Act, signed in 1996 by President Bill Clinton, does not recognise gay unions sanctioned by states.