Legislators in the US state of Washingon have unveiled proposals to extend all the rights of married couples to same-sex partners.

The state already has some protection for registered gay and lesbian couples through domestic partnerships and the new bill would establish equal protections without legalising same-sex marriage.

It is sponsored by Democratic state House member Jamie Pedersen, one of six out gay people in the legislature. His party controls both the Senate and the House.

The proposed legislation has the support of the state Governor.

“The purpose of this legislation is to provide a way for us to talk about how our families are harmed concretely by their exclusion from civil marriage,” Mr Pedersen told the Seattle Times.

“We hope that sooner, rather than later, we’ll be here talking about a marriage bill.”

At present same-sex marriage is legal in Massachusetts and Connecticut, while civil unions that carry all the state rights of marriage are legal in New Jersey, Vermont and New Hampshire.

Federal marriage rights were denied to same-sex couples by the 1996 Defence of Marriage Act (DOMA).

States are not required to “treat a relationship between persons of the same sex as a marriage, even if the relationship is considered a marriage in another state.”

DOMA also prevents the federal government from gay and lesbian relationships as marriage “for any purpose,” even if the marriage is recognised by one of the states.

President Barack Obama is committed to the repeal of DOMA, but does not support gay marriage.

According to a statement on civil rights on the White House website the administration will pass legislation “that would ensure that the 1,100+ federal legal rights and benefits currently provided on the basis of marital status are extended to same-sex couples in civil unions and other legally-recognised unions.”