WASHINGTON -- The upcoming U.S. census "won't ask and won't tell" if same-sex couples are married.

The federal government says same-sex couples in California and Massachusetts who tell the 2010 census that they are married.. Will be reported instead as "unmarried partners."

Census officials say the congressional passage of the "defense of marriage act" prevents them from recognizing same-sex marriages.

Critics of the policy say it will effectively make gay marriages disappear from federal records and make it impossible to follow demographic changes in same-sex families.