23 February 2011
Last updated at 12:56 ET
The US government says it will no longer defend in the courts a law which bans the recognition of same sex marriage.
US Attorney General Eric Holder said the administration would no longer defend the Defense of Marriage Act (Doma).
Doma defines marriage as “only a legal union between one man and one woman as husband and wife”.
Until now the US has defended the law in challenges to its constitutionality.